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Article deals with the design of a model of a tensometric measuring system. Authors in this article describes the procedure for measuring the system response to a step change in load and then the procedure creating a model. The article shows a graphical comparison between the measured ones system characteristics and simulated system characteristics. The conclusion is given calculated errors between measured system characteristics and simulated system characteristics.

Microwires can be used for different purposes and one of them is magnetic field measurement. In order to better understand the behavior of the microwires when measuring the magnetic field it is necessary to know their magnetization characteristics. This article is description workplace for measuring magnetization characteristics of microwire sensors, which was carried out at the Department of Aviation Technical Preparation of the Faculty of Aeronautic.

This article deals with a concept of the microwire magnetometer for mapping of magnetic fields using Unmanned Aerial Vehicles (UAVs) that have been developed at the Faculty of Aeronautics at the Technical University of Kosice. A UAV equipped with this type of sensor will be used to map mineral deposits, archaeological sites, locate pipelines and survey in specific areas of interest where conventional systems cannot be used or are impractical. The system in development uses a magnetic microwire sensor based on the Residence Times Difference (RTD) principle of magnetic field measurement. With this type of a fluxgate magnetometer several nT sensitivity was achieved - by the prototype, however the sensitivity below nT is expected to be achieved based on the results of the initial tests.

This paper provides a brief overview of the UTM structure focusing on technological capabilities outlined for robust communication. Selected general aspects for UAS communication link consideration were introduced as well as two potential candidates. The core of this paper examines a MAVLink communication protocol as potential candidate for data exchange medium betweenU TM provider and UVS to aggregate necessary data and information for unmanned traffic management such as remote identification, flight approval, tracking and traffic monitoring.

A rise in usage of unmanned aerial systems (UAS) in commercial and civilian applications as a result of the recent advancement in manufacturing processes, communications, and networking technology led to the demand for access to non-segregated airspace. The steady development of UAS has created a dynamic environment moving at faster pace than manned aviation. In particular, there is an intense pressure on operations in very low altitudes where market is driven by new business models. Commercial UAS operators are expected to monitor weather, changes in airspace structure, avoid buildings and temporary obstacles, consider potential risks arising from the ground, and maintain separation from manned aviation. On the other hand, authorities are expected to monitor, and control unmanned aerial traffic as well as enforce the airspace rules. To address this arising requirements unmanned traffic management is being developed and deployed in numerous countries, which aims to enable safe and efficient operations of highly automated UAS in automated unmanned traffic management (UTM) system developed on foundations of modern technologies such as artificial intelligence, the Internet-of-Things, 5G networks while considering the need to address cybersecurity requirements. Among cybersecurity requirements a potential candidate with promising applications is blockchain technology, which is a distributed ledger of immutable records stored in a decentralized database. This paper discusses potential applications of blockchain technology that could support UAS operations and increase security in storing crucial flight data.

The paper presents the concept of a workplace for multirotor UAV control parameters measurement. The workplace consists of tensometric measurement devices, which measure the thrust and reactive forces of the UAV motors, and a servomechanism, which simulates angular motion for the flight control board of the UAV. The paper describes two methods of measurement, one with a fixed flight control board without the servo and one with the flight control board mounted to the servomechanism pivoting it around its pitch axis. The goal is to prove that with the servomechanism the flight control board acts more like in real flight in comparison to the tests with the fixed board.

The article deals with the development of a magnetic microwire sensor for use on board of small UAVs (Unmanned Aerial Vehicles). This sensor forms together with the analog-digital processing circuits a measurement system that can measure weak low frequency stationary magnetic fields in the range of $\pm 100 T$, safely exceeding the necessary range of the Earth’s magnetic field. The paper presents some of the results of the test measurements realized on the microwire samples, which can be used as the sensor core in the RTD (Residence Times Difference) type magnetometer.

The rapid development of industry results in large energy consumption and a negative impact on the environment. Pollution of the environment caused by conventional energy sources such as petrol leads to increased demand for propulsion systems with higher efficiency and capable of energy-saving and emission reduction. The usage of hybrid technology is expected to improve energy conversion efficiency, reduce energy consumption and environmental pollution. In this paper, the simulation platform for the hybrid unmanned aerial vehicle (UAV) has been built by establishing the subsystem models of the UAV power system. Under the two chosen working conditions, the conventional cruise flight mission and the terrain tracking mission, the power tracking control and Q-Learning method have been used to design the energy management controller for the hybrid UAV. The fuel consumption and pollutant emissions under each working condition were calculated. The results show that the hybrid system can improve the efficiency of the UAV system, reduce the fuel consumption of the UAV, and so reduce the emissions of CO2, NOx, and other pollutants. This contributes to improving of environmental quality, energy-saving, and emission reduction, thereby contributing to the sustainable development of aviation.

The article presents the realized electronic monitoring system of actuating operations for small UAVs based on the Intel MAX 10 FPGA and the NXP LPC1768 microcontroller. The system is currently optimized for measurement of the pulse-width modulation control in eight parallel channels. The development of this system was realized based on two requirements, requirement to optimize the coefficients of the autopilot like ArduPilot, which is still frequently used in small unmanned multirotor aircrafts and the requirement to record the actuating operations of the small UAV operator to make it possible to optimize and objectively evaluate the training process through the analysis of the recorded parameters. The article shows the results of test measurements realized on the measurement fixture and measurements of an in flight hover test.

Noise analysis of inertial sensors can be performed using many methodologies. One of the advantageous methods supported also by the IEEE is the noise analysis using Allan variance. But for the evaluation of the analysis results it is necessary to know how to correctly interpret the results even in the case if the measurements are influenced by interference. The article deals with the influence of the periodical interference on the noise analysis of the inertial sensors. Selected cases when the noise has dynamic characteristics, is non-stationary and varies in time were analyzed.

The calibration method using the spectral analysis is based on the continuous sensor rotation around the sensitivity axes placed perpendicularly to the plane of the vector of gravity. The rotation can be continuous, because for the calculations based on the spectral analysis the assignment of samples to the particular degrees of the sensor rotation is not required. For this calibration methodology only the final amount of measured samples is substantial and that enables creation of an automatized workstation for the accelerometer calibration with the focus on the determination of bias and scale factor constants of the sensors' channels.

The paper deals with the robustness of the calibration algorithms based on the neural networks against external interference. The chosen neural networks distinguish only in the learning rule. For a comparison the backpropagation, backpropagation with momentum and resilient propagation learning algorithms were chosen. The algorithms were examined from the calibration speed and accuracy point of view defined by the specified criterions. Tests were performed in the form of simulations with the applied measured periodical interference and the periodical interference with the random occurring amplitude modulation. The goal of the article is to prove the fundamental robustness of the algorithm against the interference and the response of the chosen algorithms to the various external interference types.

The presented paper deals with the calibration methodology based on the spectral analysis. One of the advantages of the methodology is that for the accelerometers and magnetometers which are a part of the inertial measurement unit (IMU) only one calibration experiment is required. The methodology is based on the sensor rotation around one of three sensitivity axes placed perpendicularly to the plane of the vector of gravity. The positioning of the sensors can be performed stepwise but also continuously because there is no requirement for the assignment of samples to the particular degrees of the sensor rotation.

the composite materials are more often used materials in aerospace industry. The defectoscopy of these materials are critical for their application in structural parts of constructions. Presented paper describes the simulation - experimental verification of contactless tensile stress measurement method. The glass fibre composite I-beam was prepared for experimental verification. The same beam was modelled and simulated in ANSYS to compare with experimental results. The simulation and experimental results are presented in the paper.

The number of unmanned aerial vehicles (UAVs) incidents in the world is increasing, because it is not difficult to buy multirotor UAVs that are inexpensive and technologically well equipped. This is the reason why the development of detection systems gains importance. Radar systems and specific frequencies detectors have their limitations, so it is necessary to develop different sensing methods. The presented paper deals with the possible lowrange method to detect electric-powered multirotor UAVs based on the low frequency magnetic fields generated around them. The results of the realized experiments with magnetic field sensors show that the UAV creates measurable magnetic fields disturbances that could be used as an intrusion indicator.

skCUBE is 1U cubesat designed and developed in Slovakia over a period of years from 2012–2015 with expected launch in to the low-Earth orbit in 2017. It carries an experimental very-low-frequency (VLF) radio waves detector, which will attempt to record whistlers — radio signals from dispersed radio frequency components of lightning's. A lot has been found about these radio waves caused by classical lightning in past already, but there is not much known about VLF radio from rarer terrestrial luminous events (TLE) like gigantic jets. Gigantic jet is a type of lightning directed upwards between storm clouds and lower ionosphere. We will attempt to use VLF data from this detector to learn more about these phenomena. However, in essence we want to study peculiarities in all detected VLF spectrums regardless of type of lightning together with properties of Earth's ionosphere. Due to design limitation of skCUBE, we placed the VLF detector inside the satellite. The VLF detector consists of air-core loop antenna, trans-impedance amplifier and microcontroller capable of signal processing directly on-board. It works in two modes, slow and fast. Slow mode will detect gradual changes in VLF radio on timescales comparable to the whole orbit of satellite (< 90 minutes), whereas the fast mode will be capable of fast sampling of short events like whistlers (< 0.1 seconds) based on excess in pre-determined power flux density threshold.

The paper presents the experimental results of the transfer characteristics measurement of contactless microwire sensor embedded into a glass fibre composite material. This kind of sensor reacts on several physical quantities, especially on temperature, mechanical stress and external magnetic field. Sensor reacts well on the change of mechanical stress and external magnetic field. Basic sensor description, experimental conditions and experimental procedure are described in the presented paper. The experimental results and the measured transfer characteristics are presented and discussed.

The aim of the article is to demonstrate that calibration of 3D vector magnetometers using neural networks is possible even in the conditions with external interferences, eliminating the requirement to choose environment. In addition, the selected calibration method is position-independent and therefore no positioning devices are necessary. Given the dominant systematic errors of the selected HMC 5883L sensor an inverse model that takes into account the multiplicative, additive and orthogonality was elected. Calibration was performed initially in the laboratory without additional interference. Next, calibration took place in the environment with additional periodic harmonic disturbance and the results were compared.

The communication link between the unmanned aerial vehicle and its ground station is a critical part of the complete unmanned aerial system. Nowadays, there are several kinds of the communication interfaces with different parameters such as operational frequency, data throughput, transmitting power etc. This article deals with the possibility to use the latest generations of mobile telecommunication systems, specifically 3th generation and 4th generation, for the purpose of the unmanned aerial vehicle communication interface.

The information obtained from magnetic fields measurements can be utilized in many areas and can be also used for the purpose of an object security. The article deals with experimental results obtained with the VEMA-04, four channel relax-type vector magnetometer. The magnetometer was able to detect the tested common phenomena and proved the possibility to use it to secure objects with evaluation of the disturbances in the measured magnetic field. This subsystem can be integrated into the already existing security systems, since the magnetometer utilizes a microcontroller for communication with other systems.

Knowledge of real parameters of the sensors' transfer characteristics is very important for a correct system function. The paper presents a novel easy-to-use iterative calibration algorithm for a vector field sensor's accuracy improvement, which can be successfully applied to the estimation of the calibration constants of the 3-axis accelerometers that are commonly used in the role of inertial sensors. The theory is based on the neural network that creates an inverse function to the uncalibrated sensor's transfer function. Learning process of the neural network uses a gradient methodology applying total differential on the scalar error equation. The analyzed theoretical principles are supplemented by simulations and experimental measurements. The performed simulations and experiments confirmed that the algorithm successfully converges, which enables a precise estimation of the calibration constants. Other advantage of this methodology lies in the attitude independent sensor discrete random rotation in the 3D space during the calibration procedure without the need of any precision positioning calibration platforms.