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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.

Turbojet engines are nowadays mostly controlled by full authority digital engine control (FADEC) systems using electronic engine control units. Microprocessor based control systems allow application of sophisticated control algorithms. The aim of the presentation is to show the state-of-the-art control systems and perspective algorithms based on integrated situational control methodology, which are aimed to increase the efficiency, reliability, and safety of operation of turbojet engines. Situational control is applied in this case in control and management of turbojet engines under all operational conditions including atypical ones using intelligent elements and strong integration with diagnostic systems. The concept of highly integrated control and diagnostic system is leading to a novel modular control framework with morphing structure and a degree of intelligence. It will be presented for application on general turbojet engines with specific implementation tested on a small turbojet engine in laboratory conditions as a proof of concept with positive results. These algorithms are designed as modular and robust with perspective applications in control of other large scale systems.

The state of present technologies in technical and also non-technical practice is represented by growing complexity of systems. A turbojet engine as a complex system is multidimensional highly parametric system with complex dynamics and strong non-linear behavior with stochastic properties. Its particular property is operation in a wide spectrum of changes of its operating environment (e.g., temperatures from -60 to +40 °C, different humidity, different pressures, etc.). If we want to secure optimal function of such system, it is necessary to develop models and control systems implementing the newest knowledge from the areas of automation, control technologies preferably with elements of artificial intelligence (AI). The present control systems and dynamic models are often limited to control or modeling of a complex system in its certain (operational) states. However, in practice the turbojet engine finds itself in very different operating conditions that influence its parameters of operation and characteristics. To create progressive control algorithms for a turbojet engine, it is necessary to design models in the whole dynamic spectrum of the modeled system including its erroneous states. Furthermore we need to design a control system that will secure operation converging towards optimality in all eventual states of working environment and also inner states of the system represented by its parameters. This leads to the need of having increased intelligence of control of turbojet engines that reduces workload of a pilot and also increases safety of operation. Safety represents a decisive factor in design of control systems of turbojet engines and is presently bound with increasing authority of them. The present trend designates such control systems as FADEC – Full Authority Digital Engine Control, however in reality such control systems have different levels of authority, intelligence and come in very different implementations. These are often not presented as they are intellectual properties of commercial companies. The article will be aimed on description of some present trends in development of FADEC systems and own proposals of methodologies leading towards design and implementation of a FADEC system with high level of intelligence able to solve all operational situations of a turbojet engine. This is strictly bound with presentation of modern methods of modeling of turbojet engines and the use of advanced methods of mainly sub-symbolic artificial intelligence. The proposed methods are all tested in real-world environment using a small turbojet engine MPM-20 in our laboratory setup. Therefore the article will also deal with approaches in digital real-time measurement of state parameters of this engine and design of control algorithms from engineering standpoint.

The use of alternative fuels to traditional kerosene-based ones in turbo-jet engines is currently being widely explored and researched. However, the application of alternative fuels in the area of small turbojet engines with thrust ratings up to 2 kilo-newtons, which are used as auxiliary power units or to propel small aircraft or drones, is not as well researched. This paper explores the use of ethanol as a sustainable fuel and its effects on the operation of a small turbojet engine under laboratory conditions. Several concentrations of ethanol and JET A-1 mixtures are explored to study the effects of this fuel on the basic parameters of a small turbojet engine. The influence of the different concentrations of the mixture on the start-up process, speed of the engine, exhaust gas temperature, and compressor pressure are evaluated. The measurements shown in the article represent a pilot study, the results of which show that ethanol can be reliably used as an alternative fuel only when its concentration in a mixture with traditional fuel is lower than 40%, yielding positive effects on the operating temperatures and small negative effects on the speed or thrust of the engine.

By the term of flight dynamics, we refer to the general study of performance, stability and control particularly for VX- 3 Unmanned Aerial Vehicle (UAV) during the flight. Each of these aspects of aircraft flight is described separately through the defined flight regime conditions and considering the specific aircraft configuration and geometry aspects. The calculation of an individual flight mode involves the analysis and definition of kinematic and dynamic parameters that are entered into the equations of motion derived from 2nd Newton's Law. The result of the calculated performance is shown in the diagram of the dependence of height and speed (H-V diagram) with a parametric representation of other quantities of interest. Performance diagram show the envelope, i.e. the operating area of an aircraft with optimal modes of interest and maximum operational limitations (e.g. maximum altitude or flight ceiling).

One of the praxeological problems of safe and sustainable air transport (airfreight transport/air cargo, and air passenger transport) is the prevention and management of risks by competent staff, with the support of modern information and communication technologies. This paper presents an educational information model and software for the airport network and information systems risk assessment, primarily intended for aviation education and training of professionals for ensuring safe and sustainable air transport. The solution to the problem is based on the application of the fuzzy logic method in the air transport environment. Based on a fuzzy expert model, the selected scenario, and the input data established separately for airport assets by a group of 23 experts from aviation practice and a university, the following three assessments of airport network information system assets were constructed: Asset A2 (meteorological information systems) has an insignificant risk with an estimated 0.1162, and assets A1 (air traffic control and management (ATM), navigational aids and approach) and A3 (runway monitoring system) received a low risk of airport network and information systems (NIS) security with ratings of 0.2623 and 0.2915, respectively. An airport NIS risk assessment was aggregated (0.2288), indicating a low degree of security risk to the airport&rsquo, s network and information systems. The aggregated risk assessment of airport NIS, including financial loss data, was calculated as 0.1438, representing a low degree of security risk to the airport&rsquo, s network and information systems. Scenarios for evaluating airport assets are changing for students during education. The results of the developed model and its software will be part of the Simulation Center of the Faculty of Aeronautics.

An original swarm-based method for coordination of groups of mobile robots with a focus on the self-organization and self-adaptation of the groups is presented in this paper. The method is a nature-inspired decentralized algorithm that uses artificial pheromone marks and enables the cooperation of different types of independent reactive agents that operate in the air, on the ground, or in the water. The advantages of our solution include scalability, adaptability, and robustness. The algorithm worked with variable numbers of agents in the groups. It was resistant against failures of the individual robots. A transportation control algorithm that ensured the spreading of different types of agents across exploration space with different types of environments was introduced and tested. We established that our swarm control algorithm was able to successfully control three basic behaviors: space exploration, population management, and transportation. The behaviors were able to run simultaneously, and space exploration (the main goal) was never stopped or interrupted. All these features combined in a single algorithmic package represent a framework for future development of swarm-based agent systems applicable in a broad scope of environments. The results confirmed that the algorithm can be applied to monitoring, surveillance, patrolling, or search and rescue tasks.

Advanced control in the area of turbojet engines defines many different applied complex control strategies. Highly theoretical approaches and designs are often presented in this area. The article is aimed at practical aspects of adaptive controller design for a class of small turbojet engines in triple loop control architecture. The article presents a non-linear dynamic model of a small turbojet engine taking in account the environmental conditions, which it operates in. The designed triple loop control architecture shows increased precision of control keeping acceleration schedule of the simulated engine and is not susceptible to outer disturbances. The article shows pilot dynamic simulation tests, showing feasibility of the taken approach. It can also be used for other classes of turbojet engines as well other similar technical systems. Pokročilé řízení v oblasti proudových motorů definuje mnoho různých aplikovaných složitých strategií řízení. V této oblasti jsou často prezentovány vysoce teoretické přístupy a návrhy. Článek je zaměřen na praktické aspekty návrhu adaptivního regulátoru pro třídu malých proudových motorů v architektuře řízení s trojitou smyčkou. Článek představuje nelineární dynamický model malého proudového motoru s ohledem na podmínky prostředí, ve kterém pracuje. Navržená architektura řízení s trojitou smyčkou ukazuje zvýšenou přesnost řízení při dodržení harmonogramu zrychlení simulovaného motoru a není náchylná k vnějšímu rušení. Článek ukazuje pilotní dynamické simulační testy, které ukazují proveditelnost zvoleného přístupu. Může být také použit pro jiné třídy proudových motorů a další podobné technické systémy.

The purpose of this paper is to develop a fuzzy model of the risk assessment for environmental start-up projects in the air transport sector at the stage of business expansion. The model developed for the following software will be a useful tool for the risk decision support system of investment funds in financing environmental start-up projects at the stage of market conquest. Developing a quantitative risk assessment for environmental start-up projects for the air transport sector will increase the resilience of making risk decisions about their financing by the investors. In this paper, a set of 21 criteria for assessing the risk of launching environmental start-up projects in the air transport sector were formulated for the first time by presenting inputs in the form of a linguistic risk assessment and the number of credible expert considerations. The fuzzy risk assessment model, based on expert knowledge, uses linguistic variables, reveals the uncertainty of the input data, and displays a risk assessment with linguistic interpretation. The result of the paper is a fuzzy model that is embedded in a generalized algorithm and tested in an example risk assessment of environmental start-up projects in the air transport sector.

The purpose of this paper is to develop an applied fuzzy model of information technology to obtain quantitative estimates of environmental start-up projects in air transport. The developed model will become a useful tool for venture funds, business angels, or crowdfunding platforms for the development of innovative air transport businesses. Obtaining a quantitative estimate of the environmental start-up projects will increase the sustainability of the decision making on the security of financing of such projects by investors. This article develops a fuzzy evaluation model of project start-ups in air transport as an application of our neuro-fuzzy model in a specific air transport environment. The applied model provides output ranking of start-up project teams in air transport based on a four-layer neuro-fuzzy network. The presented model declares the possibilities of the application to solve these economic problems and offers the space for subsequent research focused on its usability in several areas of start-up development, in sectors and processes differentiated. The benefits are also visible for several types of policies, with an emphasis on decision-making processes in regulatory mechanisms to support the state funding in Slovakia, the EU etc.

Gas turbine engines are used throughout many industrial applications mostly including energy and transportation fields. Their efficient and reliable operation is therefore essential. This paper focuses on a catastrophic failure occurred in a micro turbojet engine and its goal is to identify thermodynamic properties that can be measured during the operation and can serve to identify the impending bearing damage. Furthermore, once the problem has already occurred, the authors offer a method to safely run down the engine in contrast to the original control system, which tried to continue normal operation of the engine resulting in more severe damage. The results that were obtained for a small scale device here, can be applied to larger scale machines as well, to improve control system reaction and provide advanced diagnostic capabilities.

Adaptive control is one of the possible methodologies aimed to increase the efficiency of controlled operation of complex systems. Highly theoretical approaches are often presented in design of adaptive control algorithms. The article is aimed at practical aspects of adaptive controller design for a class of small turbojet engines. Such engines can be modeled as non-linear complex systems operating in a broad range of environmental parameters as presented in the article. The designed triple loop control architecture shows increased precision of control keeping acceleration schedule of the simulated engine and is not susceptible to outer disturbances. This approach can also be used for other classes of turbojet engines as well other similar technical systems

A diagnostic system is one of the key components securing the safety of operation of a turbojet engine. There are many different engineering approaches how to design engine diagnostic systems applied in real-world conditions. We propose a novel approach for a diagnostic system design to be applied on the object of a small turbojet engine using thermal diagnostics combined with a more traditional model based approach. The combination of these two approaches together with application of methods from the area of computational intelligence create a hybrid diagnostic system, which can be integrated with a control system of the engine. The article also deals with experimental validation of the designed diagnostic system on the object of a small turbojet engine iSTC-21v in laboratory conditions.

The purpose of the paper is to present a comprehensive expert model created to obtain the quantitative safety risks assessment of environmental projects’ implementation in the aviation sector, within the investment phase of the project life cycle. The successful implementation of aviation environmental projects depends also on the security risks of the projects, their implementation, and the team implementing them. The complex expert model will allow increasing the degree of validity of the decision on the security risks of project implementation in the aviation sector. On one hand, the developed model uses the quantitative estimates of the project on various indicators and it is based on different models, and on the other hand, it uses the experience, the knowledge and the expertise of the project, and the security experts in the subject area. The model is based on the neuro-fuzzy network. It enhances the accuracy and the objectivity of the project evaluation within the investment phase of the project life cycle. Copyright © 2020 Praise Worthy Prize - All rights reserved.

Modern turbojet engines mainly use computerized digital engine control systems. This opens the way for application of advanced algorithms aimed at increasing their operational efficiency and safety. The theory of robust control is a set of methods known for good results in complex control tasks, making them ideal candidates for application in the current turbojet engine control units. Different methodologies in the design of robust controllers, utilizing a small turbojet engine with variable exhaust nozzle designated as iSTC-21v, were therefore investigated in the article. The resulting controllers were evaluated for efficiency in laboratory conditions. The aim was to find a suitable approach and design method for robust controllers, taking into account the limitations and specifics of a real turbojet engine and its hardware, contrary to most studies which have used only simulated environments. The article shows the most effective approach in the design of robust controllers and the resulting speed controllers for a class of small turbojet engines, which can be applied in a discrete digital control environment.

In order to efficiently control passenger aircraft in general., the control process is usually adapted according to flight situations. A system for selection of a particular flight situation contains complex decision making algorithm using a lot of sensors. The aim of the paper is to present a very simple., yet efficient approach of a basic flight phase classification., which is applicable in small unmanned airplanes., which have a limited computational and sensor capabilities. The flight phase selection system can be then implemented in an intelligent control and flight envelope protection system of such UAV., which are also presented in the paper.

This article presents development of aircraft on board power systems from the onset of the first simple systems that took electrical power of a minimal value and their gradual development and expansion into high-performance electrical systems that are currently replacing other power systems - pneumatic and hydraulic. There is a reference to the undisputed benefits of electrical and electronic systems for managing individual operations. The article presents the vision of the All-Electrified-Aircraft as well as an Electric-Aircraft as one of the possible solutions to the future of transportation in view of the current environmental situation. We also refer to SEPS – Superconducting-Electrical-Power-Systems, which will require a complete overhaul of the power engineering architecture.

Experimental identification as one of the possibilities of creating mathematical models of complex systems is a fast, simple and easy-to-use methodology. Even with a low percentage of knowledge of the modelled object (functionality, internal bonds, etc.) it is possible to obtain a mathematical model with high quality - similarity - verification. The disadvantage of experimental identification is the necessary existence of a functional complex system and a measuring - sensing apparatus. The Laboratory of intelligent control systems of aircraft engines has four full-featured functional systems - small and micro turbo compressor aviation jet engines. Experimental identification of small jet engines based on the measured transition characteristic is being researched using these engines. The question and topic of this article is to verify the possibilities and ways of creating mathematical models by experimental identification based on the acquired - measured transition characteristics for the smallest category of aircraft engines - micro turbo-compressor jet engine and evaluate obtained simulation models of different complexity.

Information about temperature distribution in the thermal field can serve as one of the major parameters for turbojet engine diagnostics and can contribute to extended technical lifetime of the engine. The aim of the submitted paper is to perform a basic analysis of the thermal field distribution during various operational modes of a small turbojet engine. As the object for thermal field investigation, a small turbojet engine iSTC-21v, installed in a laboratory, was used. The thermal field has been captured by a thermographic camera. The article presents an analysis of temperature distribution in various nodes of the small turbojet engine, defining critical parts of the engine during its operation, which can be further analyzed for diagnostic purposes. It is expected that this analysis can also be applicable for high power jet engines.

In this paper, a mobile application and a server-side system is designed for remote physical system monitoring. The proposed design is usable for any system with data acquisition system from National Instruments or a system that can create a Socket connection. The application itself is the top layer of the data acquisition chain oriented on the client side. Proposed applications use the UDP protocol to transfer audio, video and data content through the network.

The presented article is aimed at the analysis of precision of a non-linear mathematical model of a small turbojet engine iSTC-21v. This precision is dependent on accuracy of the model's gain approximation methods (polynomial, interpolation, Fourier, etc.), which are investigated in the article. The hypothesis of the paper is if it feasible to achieve very high level of accuracy in this approximation and if the resulting non-linear dynamic model will be more useful in control. This is important to research in order to comply with demands on control systems in aviation like safety, reliability, while maintaining simplicity. Verification of the models has been done using the measured data from a small turbojet engine in laboratory conditions.

This paper presents the preparation work and first testing of a real-time monitoring application framework. The framework has been proposed and created for a small turbojet engine iSTC-21V. The main motivation is to provide data for educational purposes in a nearby multimedia lecture room and to wider public that is not able to access the laboratory, due to lack of room in the laboratory or travel distance. To complete this task, we took hold of our first concept and created three joint applications. LabView application for sending measured data using UDP protocol, staging server service (UDP receiver and WebSocket) for distributing data to multiple clients at a time and a sample client web application for receiving and presenting the data (WebSocket). The system is currently not in operation and will be tested after the beginning of the semester.

Small turbojet engines represent a special class of turbine driven engines. They are suitable for scientific purposes and research of certain thermodynamic processes ongoing in turbojet engines. Moreover such engines can be used for research in the area of alternative fuels and new methods of digital control and measurement. Our research, which is also presented in this article, is headed toward these aims. We evaluate and propose a system of digital measurement of a particular small turbojet engine - MPM 20. Such engine can be considered as highly non-linear large scale system. According to obtained data and experiments we propose different approaches to modeling of the engine with use of analytic experimental and certain methods of artificial intelligence as new methods of modeling of complex systems.

Adaptive sampling using a neural network and a fuzzy regulator is described as applied to computer network traffics. The objective of this approach is to maximally reduce the amount of data to be processed with preservation of acceptable measurement accuracy. The results of experimental verification of sampling efficiency are also presented that are based on the traffic data archive of a real computer network.

In this work, we compare nine methods of experimental identification (polynomial models, artificial neural networks and deterministic methods). We use measured data from the small turbojet engine iSTC-21v to create experimental models through programming environment MATLAB/Simulink. Comparing the output of these calculated models with the real measured data, we get the amount of the mean absolute error (MAE) and mean absolute percentage error (MAPE) on the basis of which we determine the accuracy of each method.

The paper deals with mathematical modeling of a small turbojet iSTC-21v with variable exhaust nozzle. We evaluate and measure the appropriate parameters that describe the engine modes during changes of the exhaust nozzle diameter. The article describes methods of experimental identification (the method of successive integration and the approximation of characteristic response) applied on a system with two inputs and two outputs. For the purpose of mathematical modeling, as well as for models evaluation, real data obtained from a small turbojet engine measurement are used.

This contribution presents an analysis and application of Kalman filtering in the field of autonomous and satellite navigation integration for a flying object. This paper deals with properties of the linearized Kalman filter, applied error models and test functionality of the proposed algorithm. An issue of the used and analyzed error models is related with analysis of the sensor properties. Errors for particular inertial measurement units are selected and their implementation to error model of Kalman filter is evaluated. Error characteristics is followed by the analyzed error models for navigation system integration. The article presents a partial solution of dissertation thesis “Integration architectures of navigation systems”, where analysis of Kalman filter leads to proposal of the integrated navigation system for UAV (Unmanned Aerial Vehicle).