A safety design method of a civil aircraft cargo door actuation system has been listed in this study in order to fulfil the requirements of airworthiness throughout the product's life circle, in which a safety design process has been illustrated to show the entire process which will have an impact on the function design. A safety analysis method of fault tree analysis has been chosen to realise the purpose, which is based on the fault modes provided from failure modes and effects analysis and the system reliability prediction results. A design refinement has been made according to the analysis results in order to realise a high safety system.

The accumulator is a crucial component of the hydraulic power for servomechanisms of the launch vehicle, which has a significant effect on the performance and the mass power. Traditional design methods are mostly based on empirical formulas, which do not meet the requirements of the fine design of aerospace products. The physical model, the mathematical model of the accumulator and joint simulation model of the energy and the control loop are established, and parameters satisfying the extreme flight operation profiles are obtained, including the discharge volume, charge volume and charge pressure. The flight data of third-stage servomechanisms of the Long March 3 series Launch Vehicle were analysed, which is consistent with the simulation data, indicating that the accumulator has exerted the maximum capability in the extreme flight condition, and the maximum mass power has been realised.

Flapping wings are known to be used not only for propulsion, but also for energy extraction from the surrounding fluid environment. In this work, the authors propose a vertical axis turbine based on flapping wings. Numerical experiments have been conducted. Results show (i) In a certain range of frequency, the vertical axis turbine equipped with flapping wings of circular or reversed-D motion trajectory demonstrates better energy extraction performance when compared to the traditional vertical axis wind turbine. (ii) For the reversed-D motion trajectory, as two airfoils begin to move apart from each other, the downstream flapping-wing takes advantage of the trailing edge vortex of the upstream flapping-wing to enhance its own energy extraction ability. However, for the circular motion trajectory, the two airfoils are usually located far away from each other. This leads to the result that the mutual influence between the two airfoils is very weak. Generally speaking, the application of flapping wings in the vertical axis turbine can improve the energy extraction efficiency in a certain range, which can provide another method for the design of a new type of vertical axis turbine in the research and industry.

The design of electrical power subsystem of a satellite is challenging since it involves many components and depends on multiple parameters including mission duration, satellite orbit, eclipse times and etc. In contrast to the existing mission specific designs, we propose a generalized and comprehensive method to design and size key EPS elements: PV array and battery, which are integral for mission success. For battery, the proposed design incorporates battery cell characteristics, round trip efficiency, degradation, eclipse load profile and operating modes. The proposed design of PV array takes into account orbit inclination and altitude. In addition, structure and geometry of PV array are also considered and used for irradiance forecasting. Reliability, power margins and power fraction for summer solstice are also factored in the design. For the planning and development of operational strategy, parameter limits are determined for depth of discharge, initial state-of-charge, final state-of-charge and end-of-charge voltage of the battery. The controller design is also presented for the EPS. The effectiveness of the proposed design methodology is verified by a case study of Mysat-1, an imaging nanosatellite developed and launched by Khalifa University.

Geographically distributed hardware-in-the-loop (HIL) testing has the potential to allow hybrid vehicle powertrain components (battery, motor drive, and engine) to be developed at geographically remote locations but tested concurrently and coupled. Inter-location internet communication links can allow non-ideal behaviour observed in a physical component in one location (e.g. an electrical drive) to be imposed on another physical component elsewhere (e.g. an ICE), and vice-versa. A key challenge is how to represent the behaviour of a remote, physical component under testing in a local HIL environment. Internet communications are too slow and unreliable to transmit waveforms in real-time and so one solution is to use a local ‘slave’ model whose behaviour and parameters are tuned based on observations at the remote location. This study proposes a multi-frequency averaging (MFA) slave model of an electric motor drive system for use in this application; it addresses a weakness in previously published work by extending the MFA model to variable frequency operation. The model was benchmarked against experimental operation (and its equivalent simulation model) in open-loop and closed-loop space vector pulse-width modulation control strategy, fixed and variable frequency operation. Results show significant reconciliation of model and experiment.

Pantograph arcing caused by Off-line of pantograph-catenary (OLPC) will generate Electromagnetic disturbance (EMD), which will affect train control system and communication system. This paper proposes a simplified model of the train and pantograph to investigate propagation characteristics of EMD from OLPC in the viaduct scenario, containing attenuation law in transverse and longitudinal directions. As a result, the electric field strength of EMD from OLPC increases with distance in transverse direction from 10m to 30m in the viaduct scenario, which is different from the ground scenario. The fitting formulas are found to research the attenuation law at different frequency points. We get the conclusion that the limit and measurement distance is not applicable for the viaduct scenario in current standard. To prove this, measurement in the viaduct scenario is completed, and the plausible evidence to explain the result is discussed. These results are useful in the measurement of radiated emissions, on-board equipment layout and the research of standard in high-speed railway.

The automotive industry is currently facing an automated driving revolution. This technology is tightly linked to societal and economic challenges: minimisation of traffic accidents, fuel consumption, traffic congestion, parking demand, and providing mobility for an ageing population, as well as to customer needs toward more personalised services. This study aims at the analysis and presentation of the current state of the art and prospects of automated vehicles (AVs) from various perspectives. This study concentrates on revision of the critical technologies, estimation of the impact on social aspects, identification of legal issues, consideration of factors in commercial success through user acceptance, and foresight carried out by other researchers. The primary material was prepared by review and analysis of research papers, standards, regulations, roadmaps, and projects in the field of AVs technology and its implementation worldwide. A SWOT analysis was performed, and it was found that for rapid AV spread, technological solutions need to be made taking into account law and regulation; user acceptance and human–robot interaction need to be solved together as part of one system.

2020 is set to see history made with the first ever servicing operation on an in-orbit satellite. Robotic orbital troubleshooters, which are expected to pave the way for a new era of space robotics, will one day shuttle malfunctioning spacecraft back and forth, refuel them, perform basic repairs or serve as temporary propulsion and steering units. The present paper looks at Space Logistics' MEV-1 (Mission Extension Vehicle-1) in particular, together with its mission to rendezvous with Intelsat IS901 and boost it into an orbit which will enable it to operate for a further five years. After five years, Intelsat IS901 will then be sent into a graveyard orbit and MEV-1 will move on to another satellite. Also mentioned is the work being carried out by Effective Space to carry out servicing and other life-extension services.

Low earth orbits are defined as orbits with altitude below 2000km, these orbits provide superior advantages for earth observations missions. The distinction between VLEO and LEO is the altitude of the former is below 500km. VLEO missions possess great advantages such as, in maritime surveillance, illegal immigration and piracy this is due to the fact that the imagery capabilities are enhanced significantly and identification of small objects in the order of 1 meter is feasible, in addition to higher frequency of intraday location inspection visits. These are some of the great benefits for home land security and national security of any country.

Physical properties of elves, jets and sprites, which are the most interesting types of high-attitude discharges in the atmosphere, are considered in the work. The results of researches of its fractal characteristics are presented. The obtained results give grounds for a deeper insight of development, relaxation of such atmosphere processes and taking into account of their action on radio systems.