Institute of Fundamental Technological Research

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.

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

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.

podwozia lotnicze, podwozie adaptacyjne, adaptacyjna dyssypacja energii

The contribution describes three innovative external airbag systems developed by the
authors for the protection of flying objects during emergency landings. The first one is the
AdBag system dedicated for small drones, which is designed to protect the carried equipment
and prevent damages to objects or injuries to people at the crash location. The second system
is external airbag designed for ultralight aircraft Skyleader 600, which provides significant
reduction of touchdown velocity and deceleration levels during emergency landings, thereby
improving protection of the pilot and the passengers. Finally, the last presented solution is the
Spring-Drop system with specialized airbag deployment technique, which is dedicated for
specialised airdrop operations where the touchdown conditions can be extremely harsh and
unexpected, while protection of transported cargo is of crucial importance. Both conceptual
studies, numerical simulations and experimental tests of the three proposed systems are
presented and discussed.

External airbags, adaptive system, emergency landing, human safety

This contribution introduces the concept of sky sailing, which combines the
advantages of airships and standard fixed-wing aircraft, albeit in a vertical plane alignment.
The proposed vehicle is equipped with rigid aerodynamic sails and auxiliary engines, enabling
navigation and control with minimal power consumption along the desired trajectory. The
proper orientation of the airship relative to the wind direction is achieved through the
adjustment of the sails' angle of attack and the use of auxiliary lateral engines. Consequently,
the system enables efficient maneuvering, particularly in windy conditions, while requiring low
energy input. In the current stage of our research, we focus on 2D sky sailing in a horizontal
plane. This study formulates mathematical model which employs a combined approach of
analytical methods and numerical simulations based on finite volume method. Then, the
corresponding control problem aimed at following the desired fly path with the lowest possible
energetic cost. The motivation behind this work stems from the potential applications of aerial
monitoring, such as crop or forest surveillance.

Airship, flight control, optimization, aerospace

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.

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

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.