Ing. Ondřej Hanuš, Ph.D.

This paper proposes data-based fault detection methods for an electromechanical actuator (EMA) with a brushed DC motor. The jam and winding short faults are considered in the study as the most prominent EMA faults. The fault detection is based on evaluating the properties of the motor current, considering the basic electromechanical parameters of EMAs. The main advantages are a non-intrusive approach utilising a commonly accessible motor current measurement, simple configurability, and the ability to detect faults under varying operation modes of EMA, including changes of speed, load, or movement profiles. The proposed methods have been evaluated with a custom testing system, and the results have proven the performance of the proposed approach to detect faults under varying operating conditions in industrial applications.

We investigated the air supply mode effects on ozone production of the surface dielectric barrier discharge in the cylindrical configuration. The air into the discharge volume between two coaxial cylinders was supplied through four nozzles axially or tangentially. Using tangential air supply, the vortex flow in the part of the discharge chamber was created. Because the active electrode was in the form of interconnected rings on the outer surface of the glass tube, we changed the airflow orientation concerning this electrode. The existence of vortex airflow affects the plasmachemical processes taking part in the discharge, and therefore, it affects discharge ozone production. We also paid attention to ozone concentration and temperature of output air measurements as a function of the duration of the experiment for both tangential and axial air supply modes. We found that the time required for the stabilization of generated ozone concentration depends on the discharge power, and for our experimental conditions, it smaller than approximately 70 s. Besides, in the case of tangential air supply into the discharge chamber, the concentration of ozone produced by the discharge is for higher discharge power increased in comparison with the concentration for the axial air supply mode.

In this study, we focus our attention on the impact of ozone (O3) and ultraviolet radiation (UV) on materials usable for three‐dimensional (3D) printing. Specifically, we have studied the potential degradative effect on the most commonly used filaments, such as polylactic acid (PLA) and acrylonitrile–butadiene–styrene (ABS). The effect has been examined on objects printed on a 3D printer and on the materials of discharge chambers of O3 generators from which they were printed. For the purpose of adequate assessment of the actual impact of O3 and UV, samples were monitored for a period of 18‐hr of exposure. The methods of Raman spectroscopy, optical and scanning electron microscopy and Fourier‐transform infrared spectroscopy (FTIR) have been employed for an objective evaluation of potential modifications. A generator equipped with a chamber printed from a new PLA filament and an active electrode system in the form of a stripes electrode, or more precisely, in the second case, a honeycomb‐active electrode, both cut out of a thin copper foil, was used for the generation of O3 and UV radiation. The tested materials showed substantial resistance to O3 exposure under the test conditions. The result of measurements suggested that these materials could be used for chambers for the O3 as well as for active particle generation. In this study, we focus our attention on the impact of ozone (O3) and ultraviolet radiation on materials usable for three‐dimensional printing.

This article presents an automated testing system for electromechanical actuators used in aviation. The paper describes the parameters and properties of the system and the possibilities of its use. Based on the data obtained from the system, a method for detecting actuator jam is proposed.

Numerous scientific disciplines such as hydrology, meteorology, oceanography or geology take advantage of remote measuring and monitoring. Data measurement in remote locations and the transmission of measured data is an essential part of these disciplines. The critical element of remote measurement and monitoring systems is a remote station. When designing such a device, it is necessary to solve issues of the construction, power system, data transfer or autonomous operation systems. This paper introduces the Autonomous Groundwater Monitoring Station with Wireless Communication which has been designed and installed in a field application. The individual parts of the station such as construction, software, hardware, wireless communication system or systems for autonomous operation are presented.

The mass flow rate inside heating, ventilation, and air-conditioning units provides important information for fault detection and diagnosis (FDD) and for performance monitoring. Most commercial units are not equipped with physical flow rate sensors, and virtual sensors (VS) offer an alternative that provides improved FDD performance. This paper presents the virtual mass flow sensor for an air handling unit with a recuperator (a fixed-plate heat exchanger). The VS is based on the heat exchange process inside the recuperator. It estimates the mass flow of air only on the basis of temperature readings from the inlet and the outlet of the recuperator. Two different approaches to the design of the VS model are described here. The first approach uses a simplified physical description of the recuperator, and the second approach uses knowledge of the recuperator performance curve. Laboratory experiments have confirmed that the proposed VS can be utilized as a substitute for a physical mass flow rate sensor for monitoring and for fault detection.

This article discusses an alternative possibility of detecting lightning discharge strike at a lightning protection system, as compared with the classical sensors based on the inductive principle (using a coil) or the principles requiring external feed, such as the application of the Faraday optical transformer. The key advantage offered by our proposed system is its indirect method of evaluating the impacted lightning protection system, which is based on the piezoelectric principle. Other advantages of the proposed system include direct independence on the lightning current passing through the downconductor and thus a lower risk of damage to the sensor by the lightning current, and absolute independence of the inner installation and, therefore, elimination of any risks for its operators and users, as well as a lower risk of an electric discharge flashover and outbreak of fire in a given structure.

The authors of the article have devised a lightning monitoring system whose positive features can be divided into two interconnected groups. The first major advantage is greater safety of people and animals living in the buildings hit by lightning discharge. This is the most important goal in terms of safety. With online diagnostication it is possible immediately to set up an evacuation regime for the object, and a rescue operation may be launched in the object well before any undesirable destructive effects of the lightning discharge have time to develop. The second major advantage is unquestionable evidence proving that an object has really been hit by lightning discharge – this particular factor can be used for insurance events, insurance policies and the work of insurance companies themselves.

With the advent of low-cost microcontroller-based monitoring devices connected to the Internet, there are novel possibilities of condition monitoring using new information sources. In this paper, we describe the architecture of an IoT-based system for monitoring of degradations of building equipment and illustrate the employment of local and cloud processing.

Diagnostika vzduchotechnických jednotek je čím dál více rozvíjející se obor vývoje a výzkumu. Častým problémem je však absence senzorů potřebných k diagnostice zařízení. Tento článek si klade za cíl stručně seznámit čtenáře s virtuálními senzory, které v některých případech můžou efektivně nahradit chybějící reálné senzory. Jako příklad je zde prezentován virtuální senzor hmotnostního průtoku vzduchu. Dále je v článku popsán experimentální systém vzduchotechnické jednotky, který vznikl pro účely testování a provádění simulací různých závad typických pro vzduchotechnické jednotky. Na základě dat získaných ze systému mohou být vyvíjeny a testovány diagnostické metody pro odhalování závad.

Monitoring systems are crucial components in many areas, especially in the airline industry. A modern aircraft is a complex machine which has to be continuously monitored and regularly checked to ensure high reliability and safety. The energy consumption-based monitoring methods represent a universal extension of the health monitoring system. In this work, the possibilities of the electric energy consumption monitoring in aviation are introduced. The available methods are summarized and discussed, and the new approach of the NILM-based algorithm is presented.

The future of the smart grids depends on the systems with the smart metering. Smart metering helps to increase energy efficiency and energy conservation of households. One of the ways this can be done is a usage of the nonintrusive appliance load monitoring (NILM). This paper presents the NILM-based algorithm which allows monitoring of individual appliances. The algorithm aims to track differences in power consumption and based on the knowledge of the systems, it is able to distinguish which appliances are operating. The operational information, that is continuously stored, can be used for early warning in a case that some of the expected states exhibit an unusual behavior.

Fault Detection or performance monitoring systems for HVAC (Heating, Ventilation, Air Conditioning) infrastructures in buildings have similar concepts. Customization of such systems (adaptation for different equipment, population of multiple units etc.) is labor- and time-consuming task, up to now provided manually. We propose an automated process for designing of FDD systems using context-sensitive combining the information from Building Information Model and ontology-based device descriptions.

HVAC units are one of the most significant sources of energy consumption in buildings. The operation of the unit is often associated with various hidden faults that appear only as an increase in power consumption. Commonly available HVAC units are not sufficiently equipped with sensors, which leads to the problems with monitoring and fault detection. This problem could be solved by means of virtual sensors that are able to estimate a desired value based on information from other data sources. This work addresses the possibility to employ virtual sensor of mass flow inside the airconditioning unit to monitor the status of the unit and fault detection. The paper describes the possibilities this type of sensor provides and situations in which it can be used with regard to its limitations. Both the sensor behavior under simulated conditions and its real usage as a source of information for fault detection is tested.

A major challenge for FDD (Fault Detection and Diagnostics) methods is unavailability of data that are needed for fault diagnostics [1], because the HVAC (Heating, Ventilation, and Air Conditioning) system is not equipped with certain sensors. Missing sensors can be supersede by virtual sensors [2]. The goal of this work is to provide unique system for research and development new virtual sensors. We developed experimental HVAC (Heating, Ventilation, and Air Conditioning) system designed for data collection and its further processing. Individual sensors with their parameters are introduced. Furthermore, the basic unit for data collecting and way of connections with sensors is described.