Innovative Urban Air Mobility (i-LUM)

The increasing level of urbanisation and traffic congestion promotes the concept of urban air mobility (UAM), which has become a thriving topic in engineering and neighbouring disciplines. The development of a suitable ground-based infrastructure is necessary to supply these innovative vehicles, which mainly includes networks of takeoff and landing sites, facilities for maintenance, energy supply, and navigation and communication capabilities. Further requirements comprise robust business and operating models for emerging service providers and regulatory frameworks, particularly regarding safety, liability and noise emissions. The objective of this study is to provide an overview of the current results and developments in the field of UAM ground-based infrastructure by conducting a systematic literature review (SLR) and to identify the most relevant research gaps in the field. For the systematic literature analysis, our search string contains vertiports and the equivalents, UAM and equivalents, and search phrases for the individual domains. In the final analysis 64 articles were included, finding a strong focus on simulations and vertiport networks, while specific case studies and related aspects like automated MRO and urban planning appear less frequently. Therefore, this article provides insights for a more holistic perspective on challenges and necessities of future UAM.

The current movement toward urban air mobility (UAM) [1] shows the importance of a ground-based infrastructure network to provide urban air vehicles (UAV). To ensure the safety aspect it is necessary to develop a system that can inspect the arrived UAV for damages. Therefore, technical concepts for inspecting UAVs for damage are elaborated. To identify the best system for technical development under the presented concepts evaluation criteria must be defined and applied. These include properties, technical systems, and other criteria such as the costs. In the first step for every UAV inspection system, the differences between the motion sequences will be examined. In the second step, there will be an investigation of the sensor systems presented. In conclusion, the systems with the best results in both parts are merged for an inspection setup for further investigations.

For the future of urban mobility, further developments in the fields of automation, communication and energy storage technologies will enable the expansion of traffic space into the air. Various concepts and scenarios of urban air mobility (UAM) are already part of current research. In addition to the investigation of relevant physical effects and system-internal constraints, a view including the external relationships and general conditions is essential for the design, acceptance and success of the UAM systems. Several projects (i-LUM, ULTRAS, UDVeo, LUV, Vertiport) with the participation of various Hamburg research institutions bundle a multitude of competences to develop UAM scenarios for the Hamburg metropolitan region and other regions. UAM scenarios are evaluated i.a. in terms of time, cost, noise, energy consumption, acceptance and the ease of integration. The evaluation considers societal interactions, legal frameworks, demand modeling, concept development, ground-based infrastructure, airspace organization and operation, as well as overall system modeling. This paper gives an overview about the disciplinary and methodical approach and setup of these UAM projects.

Public attitude toward Unmanned Aerial Vehicles (UAVs) has been extensively researched, frequently using surveys or experimental settings involving sound/noise. In this study, we present an experiment using visual stimuli, exploring not only the acceptance of UAVs as such but also of their interactions with different environments. The stimuli were pictures of quadcopters, either white or orange, with medical or commercial markings. For comparison, pictures of helicopters with the same four variations and a goose were also used. These pictures were superimposed over three types of backgrounds: urban, industrial, and rural. Twenty-four student participants took part in this study, each responding to 81 stimuli with Likert scale ratings for the acceptance and beauty of the stimuli after responding to objects that were used as a manipulation check. Reaction times for all responses were recorded. Afterward, participants completed a survey designed to identify the reasons for their judgments regarding acceptance. Our results deliver a complex view of the acceptance of UAVs. For example, the usage of the UAV had the largest impact on acceptance, with medical usage having the highest acceptance rating. Commercial usage was more accepted in industrial areas, and UAVs were more accepted than helicopters. The survey showed a heterogeneous variety and relevance of reasons for the acceptance ratings. On average, usefulness, traffic relief, reduction of privacy, and acceptance by society were indicated as the most relevant factors affecting the acceptance ratings. In general, our study suggests that the less considered visual factors of drones (salience in our study) can be expected to influence the acceptance of UAVs in addition to the noise factor. Most importantly, the physical characteristics of UAVs alone are insufficient to predict their acceptance. The purposes for which UAVs are used (that might be visually recognizable) and the environment in which they are operated play an important role in shaping public attitudes towards this new technology.

Novel magnesium-based materials are ideal candidates for use in future aviation vehicles because they are extremely light and can therefore significantly increase the range of these vehicles. They show very good castability, are easy to machine and can be shaped into profiles or forgings to be used as components for next generation aerial vehicle construction. In the case of a large number of identical components, high-pressure die casting of magnesium alloys is clearly superior to high-pressure die casting of aluminum alloys. This is due to the lower solubility of iron in magnesium and thus tool/casting life is significantly longer. In addition, the die filling times for magnesium high-pressure die casting are approximately 30% shorter. This is due to the lower density: aluminum alloys are approximately 50% heavier than magnesium alloys, which is a significant disadvantage for aluminum alloys especially in the aerospace industry. There are cost-effective novel die casting alloys, besides AZ91 or AM50/60 such as DieMag633 or MRI230D, which show very good specific strength at room and elevated temperatures. In the case of magnesium-based wrought alloys, the choice is smaller, a typical representative of these materials is AZ31, but some new alloys based on Mg-Zn-Ca are currently being developed which show improved formability. However, magnesium alloys are susceptible to environmental influences, which can be eliminated by suitable coatings. Novel corrosion protection concepts for classical aerial vehicles currently under development might suitable but may need adaption to the construction constraints or to vehicle dependent exposure scenarios. Within this mini-review a paradigm change due to utilization of new magnesium materials as drone construction material is briefly introduced and future fields of applications within next-generation aerial vehicles, manned or unmanned, are discussed. Possible research topics will be addressed.