Validation of Quad Tail-sitter VTOL UAV Model in Fixed Wing Mode

Vertical take-off and landing (VTOL) is a type of unmanned aerial vehicle (UAV) that is growing rapidly because its ability to take off and land anywhere in tight spaces. One type of VTOL UAV, the tail-sitter, has the best efficiency. However, besides the efficiency offered, some challenges must still be overcome, including the complexity of combining the ability to hover like a helicopter and fly horizontally like a fixed-wing aircraft. This research has two contributions: in the form of how the analytical model is generated and the tools used (specifically for the small VTOL quad tail-sitter UAV) and how to utilize off-the-shelf components for UAV empirical modeling. This research focuses on increasing the speed and accuracy of the UAV VTOL control design in fixed-wing mode. The first step is to carry out analysis and simulation. The model is analytically obtained using OpenVSP in longitudinal and lateral modes. The next step is to realize this analytical model for both the aircraft and the controls. The third step is to measure the flight characteristics of the aircraft. Based on the data recorded during flights, an empirical model is made using system identification technique. The final step is to vali-date the analytical model with the empirical model. The results show that the characteristics of the analytical mode fulfill the specified requirements and are close to the empirical model. Thus, it can be concluded that the analytical model can be implemented directly, and consequently, the VTOL UAV design and development process has been shortened

Infrastructural Requirements and Regulatory Challenges of a Sustainable Urban Air Mobility Ecosystem

The United Nations has long put on the discussion agenda the sustainability challenges of ur- banization, which have both direct and indirect effects on future regulation strategies. Undoubtedly, most initiatives target better quality of life, improved access to services & goods and environment pro- tection. As commercial aerial urban transportation may become a feasible research goal in the near future, the connection possibilities between cities and regions scale up. It is expected that the growing number of vertical takeoff & landing vehicles used for passenger and goods transportation will change the infrastructure of the cities, and will have a significant effect on the cityscapes as well. In addition to the widely discussed regulatory and safety issues, the introduction of elevated traffic also raises environmental concerns, which influences the existing and required service and control infrastructure, and thus significantly affects sustainability. This paper provides narrated overview of the most common aspects of safety, licensing and regulations for passenger vertical takeoff & landing vehicles, and highlights the most important aspects of infrastructure planning, design and operation, which should be taken into account to maintain and efficiently operate this new way of transportation, leading to a sustainable urban air mobility ecosystem

Superfly Amphibian

Following a Short Takeoff and Landing (STOL) mission profile, this seaplane is designed to carry 19 passengers and 1 flight crew with a range of 200 nautical miles. The seaplane is equipped with two turbo-prop engines and is economically comparable to current seaplanes in terms of servicing and operating expenses. The aircraft is capable of operating in remote locations with limited infrastructure due to its STOL abilities, allowing for increased access to difficult-to-reach areas. The seaplane\u27s design incorporates modern materials and technologies to enhance efficiency, safety, and comfort for passengers and crew. The aircraft\u27s versatility and cost-effectiveness make it an attractive option for regional air transportation, tourism, and other applications

System-of-Systems Considerations in the Notional Development of a Metropolitan Aerial Transportation System

There are substantial future challenges related to sustaining and improving efficient, cost-effective, and environmentally friendly transportation options for urban regions. Over the past several decades there has been a worldwide trend towards increasing urbanization of society. Accompanying this urbanization are increasing surface transportation infrastructure costs and, despite public infrastructure investments, increasing surface transportation "gridlock." In addition to this global urbanization trend, there has been a substantial increase in concern regarding energy sustainability, fossil fuel emissions, and the potential implications of global climate change. A recently completed study investigated the feasibility of an aviation solution for future urban transportation (refs. 1, 2). Such an aerial transportation system could ideally address some of the above noted concerns related to urbanization, transportation gridlock, and fossil fuel emissions (ref. 3). A metro/regional aerial transportation system could also provide enhanced transportation flexibility to accommodate extraordinary events such as surface (rail/road) transportation network disruptions and emergency/disaster relief responses

Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)

The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones

Introduction to Autogyros, Helicopters, and Other V/STOL Aircraft Volume III: Other V/STOL Aircraft

The period from Ciervas demonstration of his C.6A Autogiro in Farnborough, England, in October 1925, up to when Pan American World Airways ushered in jet age service to Europe with a Boeing 707-120 on October 26, 1958, was one of enormous progress in the aviation world. This progress was made primarily in the fixed-wing world. This 33-year period saw the conventional takeoff and landing (CTOL) machine achieve increases in cruise speed, range, cruise altitude, and number of passengers carried. These improvements were not, however, accompanied by reductions in takeoff and landing space required. In fact, just the opposite occurred. And with the arrival of the autogyro, and then the helicopter, fixed-wing advocates were presented with a clear challenge to fix the airplanes major shortcomings stalling and loss of control at low speed. I do not think airplane advocates felt particularly threatened by autogyros in the late 1920s because it quickly became apparent that the cruise performance of these short takeoff and landing (STOL) aircraft would never become competitive. Even the vertical takeoff and landing (VTOL) capability offered by the helicopter was relegated to a niche market. Fixed-wing advocates felt (and still feel, in my opinion) that helicopters would never take much of the traveling publics business away from their major civil airlines or trains, buses, cars, or ships for that matter. Understanding the fundamental performance problem of the CTOL is a prerequisite to learning about VTOLs and STOLs. Therefore, let me use this introduction to set the stage for an in-depth discussion of vertical and short takeoff and landing (VSTOL) aircraft

New Ways: Tiltrotor Aircraft and Magnetically Levitated Vehicles

Common issues for these systems include their possible contributions to improving mobility in congested corridors, U.S. technology leadership, the Federal role in transportation research and development, and institutional and community barriers to major, new infrastructure programs. Moreover, some Federal financing is likely to be required if commercial maglev or tiltrotor technologies are to be developed by U.S. industry over the next decade. Congress will need to clarify its objectives for supporting or encouraging these technologies before it can make wise decisions on when or whether to undertake substantial, long-term Federal programs in support of either or both of them. This report identifies several funding and management options for consideration if such goals are established

Investigation of a tilt-wing proof of concept for a high-speed VTOL jet UAV using thrust vectoring for balance

Success of Special operations forces (SOF) missions depends on a high level of situational awareness within sensitive areas of interest, especially when arriving in volatile, sensitive environments. Oftentimes intelligence, surveillance, and reconnaissance (ISR) UAS platforms expand situational awareness for small, clandestine teams for Special Operations; however, there is a demonstrable need for a high-speed, long-range platform capable of point launches and landings to improve outcomes of rapid response missions. This thesis intends to provide the fundamental mechanics of one solution to that platform centered on the premise of a conventional jet UAV being modified into a tilt-wing V/STOL UAV using its existing features.The proof of concept being explored emulates modifying a fast, conventional UAV configuration. That concept possessed a tubular carbon spar that was used as a point of rotation. Motor pods were attached to the wing for the lift system and only used during takeoffs and landings, after which, the propellers were folded away to reduce drag in cruise. Additionally, a thrust vectoring unit was added to the central propulsion system for balance under stall-speeds. The final configuration culminated into a novel tilt-wing VTOL system with the potential to add minimal weight and drag increases to the base configuration. This configuration was then scrutinized for its fundamental challenges to evaluate its effectiveness.Through the research and development of the proof of concept, several milestones were met. Solidworks Flow Simulation (SWFS) was validated for unsteady propeller analyses. Using lessons learned from this validation effort, the tilt-wing concept was found to have the best net lift characteristics over the tilt-rotor after verifying the effects of download experienced in tilt-rotors in SWFS. In fact, the tilt-rotor expressed a net loss in lift of 25% whereas the tilt-wing saw negligible losses. This fully rationalized the tilt-wing as a viable system for the mission profile. After construction and preliminary testing of a prototype, a CG condition was discovered for balancing novel VTOL concepts using separated propulsion systems. This discovery was key in demonstrating the tilt-wing proof of concept where it was shown to execute point launches and landings as intended through simulated testing where the runway footprint of the prototype model was reduced significantly

A Summary of NASA Rotary Wing Research: Circa 20082018

The general public may not know that the first A in NASA stands for Aeronautics. If they do know, they will very likely be surprised that in addition to airplanes, the A includes research in helicopters, tiltrotors, and other vehicles adorned with rotors. There is, arguably, no subsonic air vehicle more difficult to accurately analyze than a vehicle with lift-producing rotors. No wonder that NASA has conducted rotary wing research since the days of the NACA and has partnered, since 1965, with the U.S. Army in order to overcome some of the most challenging obstacles to understanding the behavior of these vehicles. Since 2006, NASA rotary wing research has been performed under several different project names [Gorton et al., 2015]: Subsonic Rotary Wing (SRW) (20062012), Rotary Wing (RW) (20122014), and Revolutionary Vertical Lift Technology (RVLT) (2014present). In 2009, the SRW Project published a report that assessed the status of NASA rotorcraft research; in particular, the predictive capability of NASA rotorcraft tools was addressed for a number of technical disciplines. A brief history of NASA rotorcraft research through 2009 was also provided [Yamauchi and Young, 2009]. Gorton et al. [2015] describes the system studies during 20092011 that informed the SRW/RW/RVLT project investment prioritization and organization. The authors also provided the status of research in the RW Project in engines, drive systems, aeromechanics, and impact dynamics as related to structural dynamics of vertical lift vehicles. Since 2009, the focus of research has shifted from large civil VTOL transports, to environmentally clean aircraft, to electrified VTOL aircraft for the urban air mobility (UAM) market. The changing focus of rotorcraft research has been a reflection of the evolving strategic direction of the NASA Aeronautics Research Mission Directorate (ARMD). By 2014, the project had been renamed the Revolutionary Vertical Lift Technology Project. In response to the 2014 NASA Strategic Plan, ARMD developed six Strategic Thrusts. Strategic Thrust 3B was defined as the Ultra-Efficient Commercial VehiclesVertical Lift Aircraft. Hochstetler et al. [2017] uses Thrust 3B as an example for developing metrics usable by ARMD to measure the effectiveness of each of the Strategic Thrusts. The authors provide near-, mid-, and long-term outcomes for Thrust 3B with corresponding benefits and capabilities. The importance of VTOL research, especially with the rapidly expanding UAM market, eventually resulted in a new Strategic Thrust (to begin in 2020): Thrust 4Safe, Quiet, and Affordable Vertical Lift Air Vehicles. The underlying rotary wing analysis tools used by NASA are still applicable to traditional rotorcraft and have been expanded in capability to accommodate the growing number of VTOL configurations designed for UAM. The top-level goal of the RVLT Project remains unchanged since 2006: Develop and validate tools, technologies and concepts to overcome key barriers for vertical lift vehicles. In 2019, NASA rotary wing/VTOL research has never been more important for supporting new aircraft and advancements in technology. 2 A decade is a reasonable interval to pause and take stock of progress and accomplishments. In 10 years, digital technology has propelled progress in computational efficiency by orders of magnitude and expanded capabilities in measurement techniques. The purpose of this report is to provide a compilation of the NASA rotary wing research from ~2008 to ~2018. Brief summaries of publications from NASA, NASA-funded, and NASA-supported research are provided in 12 chapters: Acoustics, Aeromechanics, Computational Fluid Dynamics (External Flow), Experimental Methods, Flight Dynamics and Control, Drive Systems, Engines, Crashworthiness, Icing, Structures and Materials, Conceptual Design and System Analysis, and Mars Helicopter. We hope this report serves as a useful reference for future NASA vertical lift researchers

Fused deposition modelling (FDM) to fabricate a transitional vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) for transportation of medical supplies in underdeveloped areas.

Masters Degree. University of KwaZulu- Natal, Durban.This dissertation’s work has focused on the design and development of a prototype UAV that aims to facilitate the delivery of emergency medical aid supplies to remote locations within South Africa (SA). This research has conducted a conceptualized design of a tilt-rotor VTOL UAV named Airslipper, which was entirely fabricated using FDM methods. Identification of key performance parameters within the vehicle’s mechatronic design enabled this research to conduct a simultaneous optimization on the propeller-based propulsion system and aerodynamic configuration. Execution of MATLAB’s ‘gamultiobj’ function on two parametrically formulated objective functions resulted in a UAV setup that increased flight endurance by 8 . This improvement amplified the effectiveness of this system and expanded the service radius distance by .1 m. The outcome of a stability and sensitivity analysis performed on the Airslipper’s aerodynamic surfaces provided critical information that contributed towards the vehicle’s flight characteristics. Findings indicated a stabilized design that exhibited appropriate frequency plots for both longitudinal and lateral stability modes. The addition of a plane analysis, which included viscous and inertial effects, offered essential drag and pressure coefficients, which aided in the final design. This research correspondingly conducted several CFD simulations on an Airslipper model, which allowed this work to examine further the fluid behaviour characteristics endured on the vehicle in both VTOL and Fixed Wing (FW) modes. Simulation findings revealed standard pressure distributions, which confirmed thrust and lift forces for the relevant components without performance compromise. This research proposed to experimentally investigate a correction factor for an FDM fabricated aerofoil that aimed to determine what structural effects were apparent for a printed part with varying FDM parameters. Outcomes demonstrated greater resilience to failure for parts that had reduced layer heights and increased infill percentages. Fabrication of the Airslipper comprised of 99 individually printed parts that encompassed a specific parameter combination which pertained to the design’s importance. Validating the prototype’s functionality was achieved through a series of hover tests that generated suitable data logs plots for the control response, actuator output signals, vibration metrics, and power. This research concluded by discussing the Airslipper’s design and fabrication method with further mentioning of recommendations for potential improvements