Staff

Abstract:
In this article, the authors propose and investigate a new concept of HAPS aerostat design in a modular form, which allows for sequential increasing or decreasing of the total volume, up to the desired size. In its initial form, the aerostat has relatively small dimensions but its central cylindrical part is multi-segmented and can be easily extended. The application of controllable construction couplings enables precise control of the aerostat expansion process and significantly improves its vertical mobility. The paper describes details of telescopic aerostat construction, presents a mathematical model of its vertical motion and investigates numerically two volume control strategies aimed at maximization of operation efficiency and minimization of operation cost. The results obtained reveal the main problems that have to be addressed and the factors that play a key role in design of such telescopic aerostats and control of their vertical mobility.

Keywords:
helium airship, control of vertical mobility, reduced energy consumption, optimum ascending and descending path

Abstract:
Podczas każdego lądowania samoloty są narażone na duże przeciążenia dynamiczne mające zdecydowany wpływ na trwałość i niezawodność konstrukcji nośnej. Wielkość przeciążeń, jakim poddawany jest kadłub samolotu, zależy w dużej mierze od poprawnej pracy podwozia lotniczego. Głównym elementem podwozia, który pochłania największą ilość energii kinetycznej związanej z momentem przyziemienia jest amortyzator. Optymalne działanie amortyzatora lotniczego ma decydujący wpływ na zużycie zmęczeniowe materiałów konstrukcyjnych oraz na bezpieczeństwo lądowania.
Wprowadzenie systemu adaptacyjnego, który będzie w stanie modelować charakterystykę dyssypacji po przeprowadzeniu diagnozowania energii kinetycznej związanej z prędkością przyziemienia i ciężarem samolotu, znacznie poprawi efektywność działania amortyzatora lotniczego, zwiększając niezawodność eksploatacyjną konstrukcji i bezpieczeństwo lotu.

Keywords:
podwozia lotnicze, podwozie adaptacyjne, adaptacyjna dyssypacja energii

Abstract:
In this article we propose a new concept of adaptive telescopic high-altitude aerostat designed in a modular form which allows for sequential changes of volume during the flight. The proposed telescopic aerostat can be easily enlarged or contracted due to application of multi-segmented construction, controllable segments’ couplings and precise adjustment of internal pressure obtained using additional gas tank, valve and compressor. Conducted changes of aerostat volume allow to precisely control generated lift force and to obtain desired paths of ascending and descending. The paper briefly presents development of control strategies aimed at: i) reaching the subsequent altitudes in the shortest period of time, ii) reaching these altitudes at the smallest cost defined as total work done by the compressor. The obtained results show high potential of the proposed innovative concept of the aerostat.

Keywords:
helium airship, control of vertical mobility, reduced energy consumption, optimal ascending and descending paths

Abstract:
Small drones with total mass of a few kilograms are becoming more and more popular in many applications increasing the probability of occurrence of emergency situations caused by an equipment failure or a human error. In case of a fall from a high altitude very often it is possible to use parachute rescue systems, which however require relatively long time for deployment and development of braking forces. The touchdown velocity may be large enough to exceed limit accelerations for UAV equipment. The paper presents the concept of deployable airbag systems, in particular with adaptive flow control, which provides a possible solution to the above-mentioned problems. The paper discusses the overall control and adaptation strategy. Simplified methods for mathematical modeling are proposed and formulated for an example on a cylindrical airbag. The conceptual part is concluded with the presentation of the methodology of experimental verification and results of initial tests of the integrated airbag system.