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Eddy-Current Sensor for a Tachometer

Abstract

The speed of a rotor or rotors of a turbine engine is important information on its operation. Due to the specific conditions, in which the measurement is taken in a turbine engine, which in particular applies to small engines that are becoming increasingly popular in manned and unmanned aviation, the most universal detector is the detector using the phenomenon of eddy currents. This article presents the developed detector system solution. The correct operation of a detector is conditional upon the possibility to detect the presence of a blade in the detection field in a reliable manner, while maintaining the resistance to interference. The developed system is resistant to changes in parameters due to the use of a differential system consisting of two detector coils connected in a bridge circuit, a rectifier circuit with filters acting as a demodulator and a comparator. The system works with a microprocessor performing data processing functions. The executed functional model was tested in a laboratory, which enabled to determine its characteristics in several configurations and to confirm its correct operation.

Open access
Estimation of Strength Parameters of Aviation Products Made of Polymer Composites Based on Markov Chain Theory

Abstract

The study investigates the fatigue strength of a component made of a glass composite material with polyester matrix, manufactured using a contact method (I) and by vacuum bagging (II). Modeling was carried out only for composite material II, due to significant spread of the strength of the composite material manufactured by contact lamination I, which means that such a material does not guarantee repeatability of the test results. Estimation of the composite material fatigue strength and residual strength was performed using a mathematical model based on the Markov chain theory. The model assumed that the material failure occurs at certain critical microvolume of the components operating within the plastic range. Observed relationships between the probability values and the distribution parameters for the static strength of the composite components, as well as the load values allow for deriving a fatigue curve equation. Obtained results are presented in the tables.

Open access
Posturographic Tests of Candidates for Military Pilots

Abstract

One of the many elements of the process of qualifying the candidates for military aircraft pilots is the assessment of the correct functioning of their body balance system, responsible, inter alia, for spatial orientation during a flight. That system continuously controls the spatial position of the center of body mass. To measure that value directly is a complex metrological task. That is why an equivalent measure is used in tests of standing posture stability, i.e. the position of a projection of the center of mass on a supporting plane.

Quantitative information determining the characteristics of the body balance system may be obtained in posturographic tests, which include measurement, recording and assessment of the trajectory of a projection of the examined person’s center of body mass.

At the preliminary stage, examined were nineteen candidates for fighter pilots (one woman and 18 men), students of the Polish Air Force Academy in Dęblin.

Based on the conducted measurements of the body mass center position and the stabilographic tests, the correctness of their balance system performance was assessed. The article discusses the examination methodology, presents measurement results and conclusions.

Open access
Reconfiguration of Unmanned Aircraft Control System

Abstract

Reliability of unmanned aircraft is a decisive factor for conducting air tasks in controlled airspace. One of the means used to improve unmanned aircraft reliability is reconfiguration of the control system, which will allow to maintain control over the aircraft despite occurring failures. The control system is reconfigured by using operational control surfaces, to compensate for failure consequences and to control the damaged aircraft. Development of effective reconfiguration algorithms involves utilization of a non-linear model of unmanned aircraft dynamics, in which deflection of each control surface can be controlled independently.

The paper presents a method for an unmanned aircraft control system reconfiguration utilizing a linear and nonlinear model of aerodynamic loads due to control. It presents reconfiguration algorithms, which differ with used models and with optimization criteria for deflections of failure-free control surfaces. Additionally it presents results of a benchmark of the developed algorithms, for various types of control system failures and control input.

Open access
Selected Aspects of the Low Level Automatic Taxi Control System Concept

Abstract

Taxiing of manned and remotely piloted aircraft is still performed by pilots without using a system of automatic control of direction and speed. Several reasons have emerged in recent years that make the automation of taxiing an important design challenge. The reasons are: decreased airport capacity due to the growing number of aircraft, poor ground operation conditions during poor visibility conditions, an increase in workload of pilots and air traffic controllers and the integration of simultaneous ground operations of manned and remotely piloted air vehicles. This paper presents selected aspects of the concept of a Low Level Automatic Taxi Control System. In particular, it emphasizes the means of controlling an aircraft during taxiing, accuracy requirements of the system and proposes control techniques. The resulting controller of the system is adaptable for different aircrafts. The actuators and their mechanical connections to available controls are the aircraft specific part and are designed for the particular type – in this case – a general aviation light airplane.

Open access
Supporting the Process of Aircraft Maintenance with Mobile Devices

Abstract

Maintenance of aircraft is a complex process and therefore, in order to optimize the process, integrated information systems are increasingly used. Rapid development and wide availability of mobile devices equipped with powerful processors and with a wide range of modern communication connections suggests their high usability for enterprise IT systems. In the Department of Avionics and Air Armament of the Military University of Technology (WAT) an ERP-class (Enterprise Resource Planning) system, intended to support aircraft maintenance [4] has been designed and developed. The main concept of the system is to store the aircraft related and maintenance information in a central repository, i.e. in databases hosted on a central database server. This solution ensures concurrent availability of the data to a large group of authorized users. The key components of the system include the database server and client applications, which ensure access to centralized information resources, according to assigned user rights. The project involves development of client applications using three technologies: web, desktop and mobile one. Developed client applications have successfully passed integration tests perfomed using sample maintenance data. Currently works on user authorization security and wireless data security are under way.

Open access
An Unmanned Aircraft Model for Control System Reconfiguration Analysis and Synthesis

Abstract

Reliability of unmanned aircraft is a decisive factor for conducting air tasks in a controlled airspace. One of the means of improving unmanned aircraft reliability is reconfiguration of the control system, which will allow to maintain control over the aircraft despite an occurring failure. The control system is reconfigured by using still operational control surfaces to compensate for failure consequences and to control the damaged aircraft. Development of effective reconfiguration algorithms involves utilization of a non-linear model of unmanned aircraft dynamics, in which each control surface deflection can be controlled independently.

The paper describes a non-linear model of a small unmanned aircraft with decoupled control surfaces. The paper discusses aircraft flight dynamics equations and estimated equations for controllability derivatives for each control surface, the results of comparison tests of the model and actual aircraft as well as the structure of the simulation model. The developed unmanned aircraft model may be used in development and in optimization of control algorithms for aircraft with damaged control systems as well as to test the impact of failures on dynamic properties of the aircraft.

Open access
Analysis of Heat Transfer in a Supersonic Rocket Head

Abstract

Design of supersonic H1 rocket by the Rocketry Group of Students’ Space Association (SR SKA) requires an analysis of thermal phenomena occurring in the elements particularly exposed to the high temperature gas. This paper contains a description of the methodology and the results of numerical simulation of heat transfer in the elements of the rocket head. The starting points were the flight conditions (3 characteristic points defined by altitude and Mach number) and independently calculated adiabatic temperature field of the gas. ANSYS Fluent code was used to determine the temperature field on the surface of the rocket. Computed cases were viscous and inviscid flow (for comparison). Based on the results formulated for the viscous case heat transfer boundary conditions, the numerical model and the thermophysical properties of materials were defined. The model was limited to a brass top part of the head and a part of a composite dome. Analytical and empirical method of “intermediate enthalpy” determined distribution of the heat transfer coefficient on the rocket surface. Then the transient heat transfer was calculated with the ANSYS system. It included the range from the rocket launch, moment of maximum Mach number to sufficient structure cooling. The results of the analyses were conclusions relevant to the further development work. Excessive heating of composite structures during the flight has been shown.

Open access
Flow Visualization Over an Airfoil with Flight Control Surfaces in a Water Tunnel

Abstract

This paper demonstrates the feasibility of using-a water tunnel for the visualisation of flow in airfoils with flight control systems in the form of slots and flaps. Furthermore, the issue of using water tunnels for scientific and training purposes was explained. The technology of 3D printed models for practical tests in a water tunnel was also presented. The experiment included conducting flow visualisation tests for three airfoil models: with the Clark Y 11.7% as the base airfoil and the same airfoil with a slot and a flap. Moreover, a modification to dye injection system was introduced. The presented results of flow visualisation around models with the use of dye, confirmed the effectiveness of the applied methodology. The results and conclusions may be utilized to verify most flow-related issues in hydrodynamic tunnels and can also be used as a training element.

Open access
Importance of Personal Data Protection Law for Commercial Air Transport

Abstract

In the review below the author presents a general overview of the selected contemporary legal issues related to the present growth of the aviation industry and the development of aviation technologies. The review is focused on the questions at the intersection of aviation law and personal data protection law. Massive processing of passenger data (Passenger Name Record, PNR) in IT systems is a daily activity for the contemporary aviation industry. Simultaneously, since the mid- 1990s we can observe the rapid growth of personal data protection law as a very new branch of the law. The importance of this new branch of the law for the aviation industry is however still questionable and unclear. This article includes the summary of the author’s own research conducted between 2011 and 2017, in particular his audits in LOT Polish Airlines (June 2011-April 2013) and Lublin Airport (July - September 2013) and the author’s analyses of public information shared by International Civil Aviation Organization (ICAO), International Air Transport Association (IATA), Association of European Airlines (AEA), Civil Aviation Authority (ULC) and (GIODO). The purpose of the author’s research was to determine the applicability of the implementation of technical and organizational measures established by personal data protection law in aviation industry entities.

Open access