Control of VTOL Vehicles with Thrust-direction Tilting

An approach to the control of a VTOL vehicle equipped with complementary thrust-direction tilting capabilities that nominally yield full actuation of the vehicle's position and attitude is developed. The particularity and difficulty of the control problem are epitomized by the existence of a maximal thrust-tilting angle which forbids complete and decoupled control of the vehicle's position and attitude in all situations. This problem is here addressed via the formalism of primary and secondary objectives and by extending a solution previously derived in the fixed thrust-direction case. The proposed control design is also illustrated by simulation results involving a quadrotor UAV with all propellers axes pointing in the same monitored tilted direction

A survey of free software for the design, analysis, modelling, and simulation of an unmanned aerial vehicle

The objective of this paper is to analyze free software for the design, analysis, modelling, and simulation of an unmanned aerial vehicle (UAV). Free software is the best choice when the reduction of production costs is necessary; nevertheless, the quality of free software may vary. This paper probably does not include all of the free software, but tries to describe or mention at least the most interesting programs. The first part of this paper summarizes the essential knowledge about UAVs, including the fundamentals of flight mechanics and aerodynamics, and the structure of a UAV system. The second section generally explains the modelling and simulation of a UAV. In the main section, more than 50 free programs for the design, analysis, modelling, and simulation of a UAV are described. Although the selection of the free software has been focused on small subsonic UAVs, the software can also be used for other categories of aircraft in some cases; e.g. for MAVs and large gliders. The applications with an historical importance are also included. Finally, the results of the analysis are evaluated and discussed—a block diagram of the free software is presented, possible connections between the programs are outlined, and future improvements of the free software are suggested. © 2015, CIMNE, Barcelona, Spain.Internal Grant Agency of Tomas Bata University in Zlin [IGA/FAI/2015/001, IGA/FAI/2014/006

MRS Drone: A Modular Platform for Real-World Deployment of Aerial Multi-Robot Systems

This paper presents a modular autonomous Unmanned Aerial Vehicle (UAV) platform called the Multi-robot Systems (MRS) Drone that can be used in a large range of indoor and outdoor applications. The MRS Drone features unique modularity with respect to changes in actuators, frames, and sensory configuration. As the name suggests, the platform is specially tailored for deployment within a MRS group. The MRS Drone contributes to the state-of-the-art of UAV platforms by allowing smooth real-world deployment of multiple aerial robots, as well as by outperforming other platforms with its modularity. For real-world multi-robot deployment in various applications, the platform is easy to both assemble and modify. Moreover, it is accompanied by a realistic simulator to enable safe pre-flight testing and a smooth transition to complex real-world experiments. In this manuscript, we present mechanical and electrical designs, software architecture, and technical specifications to build a fully autonomous multi UAV system. Finally, we demonstrate the full capabilities and the unique modularity of the MRS Drone in various real-world applications that required a diverse range of platform configurations.Comment: 49 pages, 39 figures, accepted for publication to the Journal of Intelligent & Robotic System

Implementation of electrical rim driven fan technology to small unmanned aircraft

Aircraft propeller performance is significantly reduced when tip speeds become sonic causing the maximum attainable airspeed of the vehicle to be limited by the propeller diameter. There are also performance losses attributable to miniature Unmanned Aerial Vehicles as the propeller to hub diameter ratio is reduced. The research conducted indicated that re-arranging a Brushless DC Motor and propeller configuration, so that it becomes rim-driven rather than hub-driven, would provide some performance and operational advantages and could inspire the design of novel high-speed Unmanned Aerial Vehicle configurations powered by hub-less, multi-stage contra-rotating electrical fan-compressors. This investigation involved analysis, design and testing a prototype, low cost, concept demonstrator Rim Driven Fan device in order to assess the feasibility of applying this technology to Small Unmanned Aircraft. It was demonstrated that Rim Driven Fan technology could be successfully applied to lift and propel a Small Unmanned Aircraft. However, the performance testing of the Rim Driven Fan demonstrated that in its prototype configuration it would not be as efficient as a conventional Brushless DC motor and propeller

Development of a dynamic model of a ducted fan VTOL UAV

The technology of UAV (Unmanned Aerial Vehicle) has developed since its conception many years ago. UAVs have several features such as, computerised and autonomous control without the need for an on-board pilot. Therefore, there is no risk of loss of life and they are easier to maintain than manned aircraft. In addition, UAVs have an extended range/endurance capability, sometimes for several days. This makes UAVs attractive for missions that are typically "dull, dirty and dangerous". With the development of technology, the application of UAVs is becoming commonplace for both military and civil missions. Examples of this are reconnaissance, surveillance, environmental monitoring, disaster observation, etc. The School of Aerospace, Mechanical and Manufacturing Engineering (SAMME) at RMIT University has designed a novel concept for a ducted-fan UAV with vertical takeoff and landing capability and the option to transition to horizontal flight. The aerodynamic analysis, preliminary and detailed design, of this ducted-fan VTOL UAV, is the first and most important step. To optimize the aerodynamic characteristics, evaluating aerodynamic coefficients and analyzing the flow patterns around the vehicle at different speeds and angles of attack is necessary. In this project, CFD plays an important role in predicting the longitudinal and lateral stability and control characteristics of a full-scale model of ducted fan VTOL UAV at both vertical and horizontal flight without any prior knowledge of existing wind tunnel or flight test data. Prior to carrying out experiments in the wind tunnel, the manufacture of ducted fan VTOL UAV was focused on. Particular attention was paid to the propulsion system as the key point. The full-scale model of UAV was produced using the Rapid Prototyping Facility at SAMME to ensure its accurate geometric shape for testing in the wind tunnel. The experiments of the full-scale UAV model with engines was conducted in RMIT's Industrial Wind Tunnel where its aerodynamic characteristics and its properties of counter-rotating propulsion system were tested. In addition, the correlation between experimental data and CFD results was evaluated and the accuracy of the dynamic model of ducted fan VTOL UAV was improved. Flight dynamics is concerned with the motion of an aircraft due to internally or externally generated forces. The ducted fan VTOL UAV stability and control derivatives are determined and used as a basis in a flight simulation environment. This simulation showed that the vehicle is stable and controllable for a range of flight speeds. Finally, a MIMO linear control system was designed to control the vehicle in hovering and low-speed slide flight. The real-time simulation and modeling in MATLAB combined with a flight-simulator showed several animations and trajectories of UAV missions with or without crosswind effect during flight. These simulations were very helpful in determining the dynamic behaviour of the vehicle under various flight conditions

First propulsion system design for ONAerospace eVTOL

Nowadays, the aviation sector is facing the main problem that affects the planet, global warming, produced by high levels of pollution. This project aims to design an aircraft powered by electric energy. Moreover, the tasks this aircraft should accomplish are the ones it was an aerial taxi. Also, it is desired that can carry out other tasks types as rescue or health emergencies. Therefore, it is intended the aircraft should take-off and land vertically, appearing the term eVTOL (electric Vertical Take-Off and Landing). In addition to this, to improve cruise performance, the aircraft should have conventional wings. Starting with the design, it has been divided into 4 parts, being this project the one in charge of the design of the propulsion system, as well as the one for the design of carrying enough energy to be able to perform the objectives of this aircraft must accomplish. These design objectives are the mass of the aircraft (3200 kg), the cruise speed (200 mph), and the maximum range that should be achieved (1000 km). Furthermore, during this project it has been initiated the own design of a ducted fan, wanting it to be as maximum efficient as possible for the performance of the ONA eVTOL. Proceeding with the design process, the path that has been followed is starting with the necessary dimensions computation of the disk area required to produce enough thrust to take-off. With this, the peak power value could be found, which is important to know which engine the aircraft needs. Also, the power through all the trip phases has been computed, to compare this power requirement with the available stored energy. With this comparison, the maximum theoretical range of the aircraft could be found. Finally, for the own design of the ducted fan, it has been tested some design techniques in a CFD simulation to see if they are suitable to be applied to the design itself. The software used for this has been SolidWorks, in particular, its tool destined for CFD simulations ¿Flow Simulation¿. In this study, it has been tested the possibility of having more than one rotor in the fan, as well as different geometries of the duct to maximize the performance of the propeller for both take-off/landing and cruise phases.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraObjectius de Desenvolupament Sostenible::13 - Acció per al Clim

Aerial Robotics for Inspection and Maintenance

Aerial robots with perception, navigation, and manipulation capabilities are extending the range of applications of drones, allowing the integration of different sensor devices and robotic manipulators to perform inspection and maintenance operations on infrastructures such as power lines, bridges, viaducts, or walls, involving typically physical interactions on flight. New research and technological challenges arise from applications demanding the benefits of aerial robots, particularly in outdoor environments. This book collects eleven papers from different research groups from Spain, Croatia, Italy, Japan, the USA, the Netherlands, and Denmark, focused on the design, development, and experimental validation of methods and technologies for inspection and maintenance using aerial robots

A Multi-Modality Mobility Concept for a Small Package Delivery UAV

This paper will discuss a different approach to the typical notional small package delivery drone concept. Most delivery drone concepts employ a point-to-point aerial delivery CONOPS (Concept of Operations) from a warehouse directly to the front or back yards of a customers residence or a commercial office space. Instead, the proposed approach is somewhat analogous to current postal deliveries: a small aerial vehicle flies from a warehouse to designated neighborhood VTOL (Vertical Take-Off and Landing) landing spots where the aerial vehicle then converts to a "roadable" (ground-mobility) vehicle that then transits on sidewalks and/or bicycle paths till it arrives to the residence/office drop-off points. This concept and associated platform or vehicle will be referred in this paper as MICHAEL (Multimodal Intra-City Hauling and Aerial-Effected Logistics) concept. It is suggested that the MICHAEL concept potentially results in a more community friendly "delivery drone" approach

Intelligent control of a ducted fan VTOL UAV with conventional control surfaces

Utilizing UAVs for intelligence, surveillance, and reconnaissance (ISR) is beneficial in both military and civil applications. The best candidates for successful close range ISR missions are small VTOL UAVs with high speed capability. Existing UAVs suffer from the design tradeoffs that are usually required, in order to have both VTOL capability and high speed flight performance. In this thesis, we consider a novel UAV design configuration combining several important design elements from rotorcraft, ducted-fan, tail-sitter, and fixed-wing vehicles. While the UAV configuration is more towards the VTOL type, high speed flight is achieved by performing a transition maneuver from vertical attitude to horizontal attitude. In this unique approach, the crucial characteristics of VTOL and high speed flight are attained in a single UAV design. The capabilities of this vehicle come with challenges of which one of the major ones is the development an effective autonomous controller for the full flight envelope. Ducted-fan type UAVs are unstable platform with highly nonlinear behaviour, and with complex aerodynamic, which lead to inaccuracies in the estimation of the vehicle dynamics. Conventional control approaches have limitations in dealing with all these issues. A promising solution to a ducted-fan flight control problem is to use fuzzy logic control. Unlike conventional control approaches, fuzzy logic has the ability of replicating some of the ways of how humans make decisions. Furthermore, it can handle nonlinear models and it can be developed in a relatively short time, as it does not require the complex mathematics associated with classical control theory. In this study, we explore, develop, and implement an intelligent autonomous fuzzy logic controller for a given ducted-fan UAV through a series of simulations