Social conscience Peter had been born into an affluent family but his father's early death, combined with the effects of the Wall Street crash, meant that his mother had to bring up her young family ...in more straitened circumstances. In 1971, with colleagues, he ran the first training course for practice nurses, and in 1972 he helped to start the first patient participation group in the UK. In 1996, he helped to raise the money to buy the Hurst water meadow close to his home in Dorchester, and he served as the honorary secretary of the charitable trust until 2010, by which time he was 92.
HEAVY LIFT? Grose, Thomas K
ASEE prism,
10/2016, Volume:
26, Issue:
2
Journal Article
The company's prototype Airlander 10, a 302-foot-long, double-hulled craftthat can go 90 mph at 16,000 feet and carry 10,000 pounds of cargo, made news twice in August: first, for completing a ...19-minute maiden test flight; and second, for ending a 100-minute flight with a nose-first "heavy landing."
Hybrid Airships (HAs) are being touted as an efficient aerial platform for various applications involving heavy cargo transportation, communications, scientific exploration, observation, and ...surveillance in the stratosphere. Hybrid airship technologies have developed significantly from mid-20th century onwards, and promise to offer unique operational advantages over conventional airships. The purpose of this review paper is to explore the concepts of hybrid airship designs that have been proposed in the recent past, and highlight the current state-of-the-art in this field. Major milestones in the development of hybrid airships are presented followed by the description of types of hybrid airships and their distinct features. This review paper focuses on dynastat type of hybrid airships, since they seem to be the most promising version of hybrid airships owing to the simplicity in their designs, and suitability for various civil and military applications. The characteristics of two types of dynastat, viz., winged-hull and multiple-hull are discussed in detail. The different aspects of the conceptual design and key disciplines including aerodynamics, dynamics, performance, thermal characteristics, structure, and optimization involved in the design of hybrid airships are reviewed in detail.
This paper presents a reliable intelligent path following control method for a robotic airship subject to sensor faults. First, an adaptive backstepping sliding mode controller is designed based on ...the six degrees of freedom model of airship, where the backstepping technique is used to obtain the desired velocities, and the adaptive sliding mode method is adopted to deal with the unknown model uncertainties. The stabilization of the whole path following control system is studied based on Lyapunov stability theory. Specially, since the measured data in the airship control system are interrelated, a data-driven soft sensor based on adaptive neuro-fuzzy inference system is designed to detect and isolate the sensor fault. Based on the developed detection and isolation mechanism, the airship control system still work well in the presence of sensor fault. Finally, simulations are given to demonstrate the effectiveness of the proposed path following strategy.
•Multidisciplinary approach for solar array area optimization is proposed.•Environment, Geometry, Aerodynamics and Energy models are coupled.•4–9% lower solar area obtained for fixed altitude, wind ...speed and deployment day.•35% lower solar area obtained if all eleven variables are allowed to vary.
This paper describes a methodology for determining the optimal envelope shape that minimizes the solar array area of a high altitude airship to be deployed at a specified geographical location. It identifies the critical day of the year and the optimal altitude of deployment on that day, and determines the smallest area of solar array that is just sufficient to meet all the operating requirements. This ensures that the airship can be deployed round the clock throughout the year at that specific geographical location, without any power shortfall. The methodology involves eleven design variables whose values are affected by parameters stemming from four disciplines, viz., Environment, Geometry, Aerodynamics, and Energy. Candidate envelope profiles are generated using a standard shape generation algorithm, and their volumetric drag coefficient is estimated using a surrogate based aerodynamic model. Envelope shapes corresponding to minimum solar area obtained by coupling the methodology to an optimizer based on Genetic Algorithms. To study the effect of the season of deployment, optimal envelope shapes were obtained for deployment on three specific days of the year (viz., Winter solstice, Summer solstice and Equinox) for an assumed altitude of deployment. It was seen that area of solar arrays needed for the airship were 4–9% lower than that for the baseline airship envelope. However, when the altitude of deployment and day of operation were allowed to vary, the optimal envelope shapes obtained had 35% lower solar area.
The robotic airships provide potential aerial platforms for various applications and require robust trajectory tracking to support these tasks. A time-specified nonsingular terminal sliding mode ...control (TS-NTSMC) scheme is proposed to address the problem of trajectory tracking for robotic airships, which can avoid the singularity problem and specify the convergence time of terminal sliding mode control. First, the problem of trajectory tracking of robotic airships is formulated. Second, a nonsingular terminal sliding manifold consisting of pre-specified nonlinear functions is proposed, and the TS-NTSMC law is designed for trajectory tracking. Time-specified convergence and stability of the closed-loop system can be guaranteed by Lyapunov theory. Finally, compared experimental simulations are given to illustrate the advantages of TS-NTSMC against NTSMC.
Abstract Ground tests are needed to determine the system status before stratospheric airship flights. In order to realize the test under complex flight conditions, this paper proposes a method of ...constructing test scenes from test events. Firstly, the different operating conditions of a stratospheric airship during its flight are analyzed. On this basis, a test scenario covering key conditions is designed. Secondly, the test scenario is described in the way of events, and the composition of events under different test scenarios is given. Finally, the test scenes are generated by the condition simulation equipment, which is applied to the ground test of the stratospheric airship. The feasibility of this method is verified.
In this paper, a three-dimensional (3-D) path-following control design for an underactuated stratospheric airship is proposed based on the parameterized path description. The desired attitude, ...velocity, and the path parameter updating law are obtained by employing the guidance-based path-following principle. The resultant system possesses a cascaded structure, which consists of a guidance loop, an attitude stabilization loop, and a velocity tracking loop. The stability analysis shows that the path-following error and all states of the closed-loop system are ultimately uniformly bounded. Simulation results demonstrate the effectiveness of the proposed controller.
