Proactive Guidance for Accurate UAV Landing on a Dynamic Platform: A Visual–Inertial Approach

This work aimed to develop an autonomous system for unmanned aerial vehicles (UAVs) to land on moving platforms such as an automobile or a marine vessel, providing a promising solution for a long-endurance flight operation, a large mission coverage range, and a convenient recharging ground station. Unlike most state-of-the-art UAV landing frameworks that rely on UAV onboard computers and sensors, the proposed system fully depends on the computation unit situated on the ground vehicle/marine vessel to serve as a landing guidance system. Such a novel configuration can therefore lighten the burden of the UAV, and the computation power of the ground vehicle/marine vessel can be enhanced. In particular, we exploit a sensor fusion-based algorithm for the guidance system to perform UAV localization, whilst a control method based upon trajectory optimization is integrated. Indoor and outdoor experiments are conducted, and the results show that precise autonomous landing on a 43 cm × 43 cm platform can be performed.

Feasibility Study of Solar Powered Unmanned Aerial Vehicle

High Altitude Long Endurance Unmanned Aerial Vehicles (HALE UAVs) could provide an improved service and/or flexibility at a reduced cost over existing systems for a vast number of civil patrol and surveillance applications. This document looks into the Feasibility and Conceptual Design of Solar Powered UAV for HALE applications. It mentions the advancements in technology of the components required to build an efficient solar powered UAV. It also provides a preliminary design methodology that can be adopted for the conceptual design of Solar Powered UAV. It also emphasizes the Aerodynamic difficulties that are faced in HALE configurations.

Should coronavirus policies remain in place to prevent future paediatric influenza deaths?

The 2019–2020 to 2020–2021 influenza seasons in the USA saw a dramatic 99.5% decrease in paediatric mortality, with only one influenza death recorded during the latter season. This decrease has been attributed to a substantial reduction in transmission, resulting from the various restrictive measures enacted during the COVID-19 pandemic, onset March 2020. The relative disappearance of influenza raises specific policy questions, such as whether these measures should be kept in place after COVID-19 transmission reaches acceptable levels or herd immunity is achieved. Given the nature of these measures as liberty restricting, it is worth discussing their intended outcome and what values they promote. Do these measures in fact promote health, or simply give the comfort of safety while undermining long-term health and individual liberties? I argue that the year-long endurance of the pandemic well into 2021 may have flattened our value landscape into one where health reigns supreme. Discussions are underway regarding whether we should modify previously accepted health risks, such as the risk of contracting influenza. In this paper, I attempt to clarify the values that motivate our policies and discuss how our present historical context has appreciated the value of health. I also provide an analysis of various pandemic policies and their relation to influenza paediatric deaths. Ultimately, the cost of certain measures on values such as education, socialisation and liberty, among others, is too high to justify their use beyond regulating the spread of COVID-19.

Conceptual Design and Feasibility Study of Winged Hybrid Airship

In recent years, hybrid airships have been identified as promising alternatives for high altitude, long endurance missions. In this study, a design methodology to study the feasibility of a winged hybrid airship powered by solar energy is presented. The proposed methodology involves five disciplines of the airship, viz., geometry, aerodynamics, environment, energy and structures that have been coupled in order to develop an optimum design which incorporates the maximum advantages of the modules. A total of fourteen design variables have been finalized, which are required to carry out the sizing of the envelope, wing, and solar panel layout. The Particle Swarm Optimization (PSO) algorithm is implemented to carry out optimization of a user-defined fitness function for given user-defined operating conditions. The optimization study is subjected to general constraints of weight balance and energy balance. Optimal solutions have been obtained for two different configurations. These are—conventional airship and winged hybrid airship. The solutions have been obtained for four different days of the year, in order to analyse any potential benefits and pitfalls of the two configurations for the varying conditions over the course of one year. The results obtained are generally found to be in excellent agreement with the imposed constraints. The winged hybrid airship configuration was found to have offered no significant benefits in comparison to the conventional configuration. The analysis of the key parameters and data values readily supports this conclusion.

Design and Implementation of a Tether-Powered Hexacopter for Long Endurance Missions

A tether-powered unmanned aerial vehicle is presented in this article to demonstrate the highest altitude and the longest flight time among surveyed literature. The grid-powered ground station transmits high voltage electrical energy through a well-managed conductive tether to a 2-kg hexacopter hovering in the air. Designs, implementations, and theoretical models are discussed in this research work. Experimental results show that the proposed system can operate over 50 m for 4 h continuously. Compared with battery-powered multicopters, tether-powered ones have great advantages on specific-area long-endurance applications, such as precision agriculture, intelligent surveillance, and vehicle-deployed cellular sites.

Proactive Guidance for Accurate UAV Landing on a Dynamic Platform: A Visual-inertial Approach

This work aims to develop an autonomous system for the unmanned aerial vehicle (UAV) to land on a moving platform such as the automobile or marine vessels, providing a promising solution for a long-endurance flight operation, a large mission coverage range, and a convenient recharging ground station. Different from most state-of-the-art UAV landing frameworks which rely on UAV’s onboard computers and sensors, the proposed system fully depends on the computation unit situated on the ground vehicle/marine vessel to serve as a landing guidance system. Such novel configuration can therefore lighten the burden of the UAV and computation power on the ground vehicle/marine vessel could be enhanced. In particular, we exploit a sensor fusion-based algorithm for the guidance system to perform UAV localization, whilst a control method based upon trajectory optimization is integrated. Indoor and outdoor experiments are conducted and the result shows that a precise autonomous landing on a 43 X 43 cm platform could be performed.

Die konsequente Nutzung modernster Technologie zum Schutz unserer Soldaten

Ferngesteuerte unbemannte Luftfahrzeuge (Remotely Piloted Aircraft/RPA) die zulassungspflichtig und aufgrund der Größe, den erreichbaren Einsatzhöhen und der Zeit, die sie in einem Flug in der Luft bleiben können, der Klasse Medium Altitude Long Endurance (MALE) zugeordnet sind, spielen in allen heutigen Einsatzgebieten eine tragende Rolle zum Schutz der Soldaten. Sie liefern 24/7-Aufklärungsergebnisse in Echtzeit und HD-Auflösung als Grundlage zur Beurteilung der Lage, der Planung von Einsätzen und zur visuellen Aufklärung in asymmetrischen Bedrohungslagen. Sie sind bereits als Aufklärungsmittel der ersten Wahl unersetzlich und könnten zukünftig auch einen unmittelbaren Schutz eigener Truppen am Boden bieten.

Comfort Evaluation of Slow-Recovery Ejection Seat Cushions Based on Sitting Pressure Distribution

Sitting discomfort not only affects the health of pilots carrying out long-endurance missions but also affects operational performance. The experimental objects included four ejection seat cushions: N1 was a fast-recovery foam as the comparison group, and the experimental groups were slow-recovery foams with different indentation force deflection (IFD), named N2 (hard), N3 (mid), and N4 (soft). The sitting comfort of 20 participants was tested on the four cushions by using subjective rating and sitting pressure distribution analysis. The results showed that compared with fast-recovery cushion N3 and N4 slow-recovery cushions have lower contact pressure and more uniform pressure distribution. Slow-recovery cushions that were too soft or too hard would reduce the comfort. No matter from the subjective rating or the analysis of the contact pressure data, the N3 cushion with a thickness of 3 cm and 65% IFD of 280 N had the highest comfort. In addition, the seat pressure distribution (SPD%) has a significant correlation with the subjective rating (p = 0.019, R = −0.98), which is more suitable for evaluating the comfort of the cushions. However, the slow-recovery cushions would show a decrease in support after a period of sitting, while the fast-recovery cushion could always maintain constant support.

Preliminary Research on a High Thrust-to-Weight Ratio of Double-Sided Composite Impeller Microturbine Engine

In some situations, the improvement of the thrust-to-weight ratio (TWR) of microturbine engines (MTEs) for energy-, economic-, and environment-related reasons can be achieved for military or civilian purposes. However, due to limitations of existing traditional MTE technology, it is difficult to meet the key requirements of small aircraft for high energy/power density and low-cost power, especially for long-endurance drone swarms. To address these problems, a novel compact concept of a high-TWR of MTE with a double-sided composite impeller (DSCI) is proposed in this research. First, the principle and structure of the concept are explained through theoretical analysis, and its potential advantages are discussed. Second, the DSCI is analyzed at the top level, and the design principle and important parameters are discussed. The DSCI and supporting jet engine are preliminarily designed. Then, their weight is estimated. Finally, theoretical analytical and numerical simulations are used to preliminarily research the performance parameters of DSCI jet engine at the design point, and the parameters are discussed. These calculations showed encouraging results, with all components of the DSCI jet engine meeting matching characteristics. Compared to the JetCat P500-PRO-GH, the DSCI jet engine has a 39.4% increase in TWR and a 36.82% decrease in specific fuel consumption (sfc). This study lays a foundation for the development of high energy/power density MTEs in the future.