Search

Tail-sitter unmanned aerial vehicles (UAVs) have gained extensive popularity in recent years due to their inherent advantages of both fixed wing and rotary wing UAVs. However, these advantages are accompanied with control challenges because of two different flight regimes and drastically changing dynamics during transition flights. This paper focuses on the design of a unified controller free from cumbersome controller switchings and applicable in all attitude range for a tail-sitter with single thrust-vectored propeller. To achieve this, both thrust vectoring model and full-regime aerodynamics model are built first, after which a complete attitude dynamics model of the tail-sitter is established utilizing the quaternion attitude description to avoid the singularity problem. An adaptive controller is then derived based on a simplified model using the Lyapunov stability theory with unknown system parameters identified online by forgetting factor recursive least square (FF-RLS) method. Flight experiments are conducted to demonstrate the feasibility and effectiveness of the proposed control scheme.

Background With the increasing role of point-of-care coagulation testing in trauma, we sought to test the reliability of the thromboelastography (TEG)6s machine in a simulated rotary wing environment. Method A two-arm study was conducted, running TEG6s quality control cartridges in a helicopter flight simulator with realistic vibration and in stable ground conditions. The flight conditions during testing included take-offs, landings and inflight emergencies such as engine failures. TEG values for R time, K time, α-angle and maximum amplitude (MA) were collected and compared with manufacturers’ normal ranges. Results 148 TEG samples were included for analysis (72 simulator arm, 76 ground arm). In the simulator arm, four of our K time values fell below the normal range and four MA values were above the normal range. All other values in both simulator and ground arms were in the normal range. Conclusion The TEG6s is a viable technology in the simulated rotary wing environment, and it is feasible to conduct further studies using human blood in live rotary wing conditions. Extreme flight conditions should be avoided during further testing.

This paper reports on the investigations made at Fraunhofer Institute for Non-Destructive Testing (IZFP) where different rotary wing micro UAS have been used to scan infrastructures including bridges and monuments at high resolutions for remote damage assessment and monitoring purposes. The aerial pictures taken at high speed and frequency have then been stitched together to obtain full 2D and 3D building reconstructions at a resolution allowing damages and cracking to be observed still in the millimeter range. With these ultra hi-res building reconstruction models a specific data base could be created for each object in order to provide extensive information for long term evaluation and life cycle management. The UAS also have been equipped with sensors for damage size estimation, which combined with an image processing software developed to allow automatic cracking pattern recognition could be used for further analysis.

Civilian rotary-wing aircraft pilots typically rely on visual information from the external environment to guide flight, but are increasingly required to operate in degraded visual environments. The current study evaluated the impact of a head-up display (HUD) upon pilot performance, perceived situation awareness and workload. A 2 × 2 repeated measures design required qualified rotary-wing pilots (N = 6) to fly in clear and degraded visual conditions both with and without the HUD. In degraded visual conditions, the HUD significantly improved pilot perceived situation awareness whilst simultaneously reducing workload. Objective flight technical performance data offered preliminary support for a positive change in pilot behaviour when using the HUD in degraded visual conditions.

There exists an increasing demand for a flexible and computationally efficient controller for micro aerial vehicles (MAVs) due to a high degree of environmental perturbations. In this work, an evolving neuro-fuzzy controller, namely Parsimonious Controller (PAC) is proposed. It features fewer network parameters than conventional approaches due to the absence of rule premise parameters. PAC is built upon a recently developed evolving neuro-fuzzy system known as parsimonious learning machine (PALM) and adopts new rule growing and pruning modules derived from the approximation of bias and variance. These rule adaptation methods have no reliance on user-defined thresholds, thereby increasing the PAC's autonomy for real-time deployment. PAC adapts the consequent parameters with the sliding mode control (SMC) theory in the single-pass fashion. The boundedness and convergence of the closed-loop control system's tracking error and the controller's consequent parameters are confirmed by utilizing the LaSalle-Yoshizawa theorem. Lastly, the controller's efficacy is evaluated by observing various trajectory tracking performance from a bio-inspired flapping-wing micro aerial vehicle (BI-FWMAV) and a rotary wing micro aerial vehicle called hexacopter. Furthermore, it is compared to three distinctive controllers. Our PAC outperforms the linear PID controller and feed-forward neural network (FFNN) based nonlinear adaptive controller. Compared to its predecessor, G-controller, the tracking accuracy is comparable, but the PAC incurs significantly fewer parameters to attain similar or better performance than the G-controller., Comment: This paper has been accepted for publication in Information Science Journal 2019

Flight within degraded visual conditions is a great challenge to pilots of rotary-wing craft. Environmental cues typically used to guide interpretation of speed, location and approach can become obscured, forcing the pilots to rely on data available from in-cockpit instrumentation. To ease the task of flight during degraded visual conditions, pilots require easy access to flight critical information. The current study examined the effect of 'Highways in the Sky' symbology and a conformal virtual pad for landing presented using a Head Up Display (HUD) on pilots' workload and situation awareness for both clear and degraded conditions across a series of simulated rotary-wing approach and landings. Results suggest that access to the HUD lead to significant improvements to pilots' situation awareness, especially within degraded visual conditions. Importantly, access to the HUD facilitated pilot awareness in all conditions. Results are discussed in terms of future HUD development. Practitioner Summary: This paper explores the use of a novel Heads Up Display, to facilitate rotary-wing pilots' situation awareness and workload for simulated flights in both clear and degraded visual conditions. Results suggest that access to HUD facilitated pilots' situation awareness, especially when flying in degraded conditions.

Orchestrating a safe landing is one of the greatest challenges for Unmanned Aerial Vehicles (UAVs). This paper aims at the autonomous localization and landing bottleneck by developing a real-time ground-based stereo visual system. This novel architecture consists of two separate perception components which are mounted with a pan-and-tilt unit (PTU) and optical sensors. Furthermore, a tracking-inspired stereo detection algorithm is proposed to improve localization accuracy. The algorithm synthesizes a Bounding Box Shrinking (BBS) approach into the Generic Object Tracking Using Regression Networks (GOTURN) method. Both datasets driven offline simulation, and online flight experiments are conducted to validate effectiveness as well as better performance of the novel system and the overall accuracy during the landing process. Also, this autonomous landing system caters for different UAV systems in operation, such as fixed-wing and rotary wing, particularly in GNSS-denied or-impaired environments.

A high-level dynamic mission allocation strategy is presented for a multi-UAV system to intercept multiple intruding targets. The objective of the dynamic mission allocation is to optimize the time-efficiency of the multiple interceptions. In the dynamic mission allocation, the optimization is carried out repeatedly in discrete-time before interceptions are completed, such that the outcome of mission allocation is improved based on feedback of real-time information. The performance of the dynamic mission allocation is proved to be superior (or at least equal) to that of a previously proposed static mission allocation.

This paper addresses the problem of deriving attitude estimation and trajectory tracking strategies for unmanned aerial vehicles (UAVs) using exclusively on-board sensors. The perception of the vehicle position and attitude relative to a structure is achieved by robustly comparing a known pier geometry or map with the data provided by a LiDAR sensor, solving an optimization problem and also robustly identifying outliers. Building on this information, several methods are discussed for obtaining the attitude of the vehicle with respect to the structure, including a nonlinear observer to estimate the vehicle attitude on \(\mathcal {SO}(3)\). A simple nonlinear control strategy is also designed with the objective of providing an accurate trajectory tracking control relative to the structure, and experimental results are provided for the performance evaluation of the proposed algorithms.

Rapid search and rescue responses after earthquakes or in postseismic evaluation tend to be extremely difficult. To solve this problem, we summarized the requirements of search and rescue rotary-wing unmanned aerial vehicle SR-RUAV systems according to related works, manual earthquake search and rescue, and our knowledge to guide our research works. Based on these requirements, a series of research and technical works have been conducted to present an efficient SR-RUAV system. To help rescue teams locate interested areas quickly, a collapsed-building detecting approach that integrates low-altitude statistical image processing methods was proposed, which can increase survival rates by detecting collapsed buildings in a timely manner. The entire SR-RUAV system was illustrated by simulated earthquake response experiments in the China National Training Base for Search and Rescue CNTBSR from 2008 to 2010. On April 20, 2013, Lushan China experienced a disastrous earthquake magnitude 7.0. Because of the distribution of buildings in the rural areas, it was impossible to implement a rapid search and postseismic evaluation via ground searching. We provided our SR-RUAV to the Chinese International Search and Rescue Team CISAR and accurately detected collapsed buildings for ground rescue guidance at low altitudes. This system was significantly improved with respect to its searching/planning strategy and vision-based evaluation in different environments based on the lessons learned from actual missions after the earthquake. The SR-RUAV has proved to be applicable and time saving. The physical structure, searching and planning strategy, image-processing algorithm, and improvements in real missions are described in detail in this study.

This study investigates the potential of rotary wing unmanned aerial vehicles (UAVs) to monitor the surfzone. This paper shows that these UAVs are extremely flexible surveying platforms that can gather near-continuous moderate spatial resolution and high temporal resolution imagery from a fixed position high above a study site. The rotary wing UAVs used in this study can fly for ~12 min with a mean loiter radius of 1–3.5 m and a mean loiter error of 0.75–4.5 m. These numbers depend on the environmental conditions, flying style, battery type, and vehicle type. The images obtained from the UAVs, and in combination with surveyed ground control points (GCPs), can be georectified to a pixel resolution between 0.01 and 1 m, and a reprojection error—that is, the difference between the surveyed GPS location of a GCP and the location of the GCP obtained from the georectified image—of O(1 m). The flexibility of rotary wing UAVs provides moderate spatial resolution and high temporal resolution imagery, which are highly suitable to quickly obtain surfzone and beach characteristics in response to storms or for day-to-day beach safety information, as well as scientific pursuits of surfzone kinematics on different spatial and temporal scales, and dispersion and advection estimates of pollutants.

This paper covers exploratory efforts that attempt to address limitations and restrictions in the operating envelope of UAVs, and proposes a conceptual solution to the problem. UAVs, like aircraft, can be categorized into two main types: fixed wing and rotary wing. A fixed wing UAV flies using wings that generate lift caused by the vehicle’s forward airspeed and the shape of the wings. The greatest advantage of fixed wing UAVs obtained from utilizing aerodynamic lift is its long range and high endurance performance. However, this primary advantage comes from the fact that most fixed wing UAVs have wings that are of a high aspect ratio, which becomes a liability in confined operating conditions. An autonomous aerial hard docking system is proposed as a system that manages to enable different UAV platforms to have operational envelopes which far exceed the operational envelopes of the constituent UAV platforms. The paper outlines necessary subsystems that need to exist for autonomous aerial hard docking capability. It presents practical requirements of the various constituent subsystems, namely the guidance and navigation subsystem, the grasping subsystem and the damping subsystem. For each of the subsystems, the challenges which have to be overcome to ensure the effectiveness of the complete system are examined. It further elaborates the testing, investigation and development steps that need to be implemented to realize this capability. It ends by elaborating on the work already underway and future development plans. Note that this paper presents a conceptual logical and architectural solution, and as such detailed analysis findings are inappropriate and premature.

This paper focuses on the design, modelling and hovering control of a tail-sitter with single thrust-vectored propeller which possesses the inherent advantages of both fixed wing and rotary wing unmanned aerial vehicles (UAVs). The developed tail-sitter requires only the same number of actuators as a normal fixed wing aircraft and achieves attitude control through deflections of the thrust-vectored propeller and ailerons. Thrust vectoring is realized by mounting a simple gimbal mechanism beneath the propeller motor. Both the thrust vector model and aerodynamics model are established, which leads to a complete nonlinear model of the tail-sitter in hovering state. Quaternion is applied for attitude description to avoid the singularity problem and improve computation efficiency. Through reasonable assumptions, a simplified model of the tail-sitter is obtained, based on which a backstepping controller is designed using the Lyapunov stability theory. Experimental results are presented to demonstrate the effectiveness of the proposed control scheme.

Rotary-wing vehicles have the potential to enable exploration of Titan at scales ranging from hundreds of kilometers to millimeters. This paper examines the flight power demands of multi-rotor vehicles (e.g. quadcopters or co-axial helicopters), considering both hover and forward flight. Specifically, this paper examines power demands of a small (1 kg) co-axial helicopter as well as a larger (350 kg) multi-rotor vehicle. In both cases the power requirements are well within the capabilities of current batteries and electric motors: the 350 kg vehicle requires 1.87 kW aerodynamic power for hover and 1.32 kW aerodynamic power for cruise at an airspeed of 9.5 m/s; the 1 kg vehicle requires 3.63 W aerodynamic power for hover and 3.17 W aerodynamic power to cruise at 4 m/s. Energy requirements of the 1 kg vehicle are driven mainly by thermal management and power required by avionics: this has a significant influence on range, endurance, and optimal flight speeds. The flight performance characteristics of both vehicles are capable of fulfilling meaningful scientific goals.

To improve flight performance of small rotary-wing unmanned aircraft under complex environment, a composite control method based on internal model control (IMC) and adaptive radial basis neural network (RBFNN) is proposed. With the analysis of the characteristics of system disturbance, an IMC system is constructed to eliminate system errors. Furthermore, an adaptive RBFNN without prior training is proposed to eliminate residual estimation errors to augment the control performance. The effectiveness of the composite control method is validated by a series of flight tests. Compared with the feedback control method, the composite control method can yield good tracking performance under wind disturbances.

QinetiQ has been the primary engineering support contractor to the RAAF airworthiness section (ASI-DGTA) since 1996. Over that 16 year time period many airworthiness investigations and assessments of structural integrity have been performed on a wide variety of RAAF aircraft types and Army rotary wing aircraft. A complete capability has been developed to manage structural fatigue in accordance with airworthiness standards, and indeed to transition the management of an aircraft from a design standard to a preferred RAAF management standard in response to capability requirements. Many important lessons have been learnt and have reinforced the capability. This paper describes some of the major programs that QinetiQ has undertaken for the RAAF, and the lessons learnt from them.

Wildlife–aircraft collisions (wildlife strikes) with civilian and military aircraft pose notable risks and economic losses. The 4 military services within the U.S. Department of Defense maintain records regarding wildlife strikes with military aircraft. Although rotary-wing aircraft operations comprise important mission components within all 4 military services, no assessment of wildlife strikes to military rotary-wing aircraft has been conducted. The objectives of this project were to 1) conduct a comprehensive analysis of data available from all military services regarding wildlife strikes with rotary-wing aircraft, and 2) provide recommendations to reduce the frequency and negative impacts of these strikes. We acquired all available wildlife strike records and parsed our database to include only wildlife strikes to military rotary-wing aircraft occurring within the contiguous United States, Alaska, Hawaii, or within near-shore areas along the coasts. We assessed the effects of year, month, time of day, event location (i.e., on- or off-airfield), and wildlife group involved on the frequency of wildlife strikes with rotary-wing aircraft. The frequency of wildlife strikes was highest during autumn (Sept–Nov; 41.6% of all strikes) and lowest during winter (Dec–Feb; 10.4%). Wildlife strikes occurred most often when aircraft were traveling en route (38.3%) or were engaged in terrain flight (28.9%). Raptors and vultures were commonly associated with wildlife strikes that caused damage to aircraft. Wildlife strikes to military rotary-wing aircraft during flight operations within the United States are both costly (averaging US$12,184–$337,281/strike event among the military services) and deadly (2 pilots were killed). Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

An experimental study was conducted to further validate whether the newly proposed flapping rotary wing is suitable for micro air vehicle design. First, the effects of two main kinematical parameters (flapping frequency and initial angle of attack) of flapping rotary wing on lift generation were discussed. It was found that a higher lift can be generated by flapping rotary wing through increasing flapping frequency at a proper initial angle of attack. Second, effect of coupled flapping motion with rotating motion on lift generation was analyzed. It is important that a larger lift was generated by flapping rotary wing than the superposition lifts from purely flapping and purely rotating motions when the initial angle of attack was less than a critical value. Finally, the comparison of the capability of lift generation from the flapping rotary wing and conventional rotary wing was given. It was indicated that the lift from flapping rotary wing was larger than that from conventional rotary wing in the range of Reynolds number from 2600 to 5000 as long as Strouhal number was determined appropriately. The present work suggests that flapping rotary wing may be a feasible and promising wing layout used in the design of micro air vehicle in terms of lift generation.

This research paper is about team Dhaksha's accomplishment in designing, developing and testing a slew of Rotary Wing Mini Unmanned Aerial Systems for entry into various international aerial robotics/unmanned aerial vehicle (UAV) competitions and civilian applications. Dhaksha, the Unmanned Aircraft System (UAS), developed by the team at Madras Institute of Technology (MIT) campus of Anna University, Chennai, Tamil Nadu, India, with its stable design presented stiff competition to other contestants during the May 2012 technology demonstration called UAVForge organized by Defense Advanced Research Project Agency (DARPA), Department of Defense, USA. Team Dhaksha on behalf of national defense research agency deployed their system as a test bed for Acoustic field testing and analysis. The team also deployed their UAS, for state police, in a religious festival, over a crowd of 20 lakh pilgrims during November 2012, to avail instant aerial images. UAS Dhaksha was deployed for investigation of structural strength of the India's tallest structure, a 300 m high Reinforced Cement Concrete (RCC) tower. Recently during the flash floods in the Himalayan river Mandakini at an altitude of 4200 m above mean sea level, Dhaksha assisted the forces in the relief and rescue operations by providing instant thermal/video images of the scene of disaster.

This article discusses the selection and analysis of materials for the manufacturing processes of the main structure for a rotary wing Unmanned Aerial Vehicle (UAV). The selection of materials was carried out through the use of several of the typical selection methodologies presented in the literature, such as the morphological matrix. Restrictions associated with aeronautical use and local availability of materials were taken into consideration.

This paper describes an integrated control demonstration in which a rotary wing unmanned aerial vehicle (UAV) landed on a moving platform using vision-based localization of the target vehicle. Three key areas are covered in this paper: the system components and integration, the control system structure and design, and finally flight test data including the first such successful landing. All the development and demonstration flights were carried out in the field, and key system challenges and lessons learned are highlighted throughout the paper. Results are given for landings carried out on both stationary and translating targets, in wind speeds of up to 15 knots. While the translating target was constrained to linear motion, there are several applications such as recovery to a land-based convoy for which this capability would be applicable. The results show that the approach adopted for this demonstration could form part of a practical solution to the problem of automated UAV recovery in both civilian and military environments.

Significant effort has been expended to develop criteria to predict the susceptibility of an air vehicle to so-called pilot-induced oscillations . Much of this work has been carried out for fixed-wing aircraft and it is only recently that their applicability to rotorcraft has started to be assessed. Real time pilot-induced oscillation identification methods provide an alternative means to at least warn the pilot that a pilot-induced oscillation is in progress so that preventative action can be taken. Existing methods, however, have some limitations and have rarely been used for rotary-wing purposes. Specifically, the existing methods assessed in this paper do not provide an indication of the severity of the event and mask the underlying data that are being used to generate the warning. This paper proposes and presents a new method to identify pilot-induced oscillations, either in near real time or as a postprocessing aid for recorded flight-test data, that addresses both of these issues. The new method, e...

Fatigue of metallic components is a concern in rotary wing aircraft. There exists a potential for loss of an aircraft if a component fatigue life does not take into account all factors than can cause life variation. Much literature was located dealing with the impact of large interference fits and cold working. Literature covering small changes was lacking. This study focused on small changes in interference such as those that could come from a tolerance on a drawing. Testing was completed on 7075-T651 Aluminum alloy lugs with steel bushings of varying interference fit. Testing three different levels of interference fit revealed three different S–N curves even though the variation from fit to fit was small. Significant improvements can be achieved in the S–N curve simply by small changes in interference. From a safety point of view these changes should be looked at as potential reductions.

This paper presents an integrated planning and control algorithm for the navigation of an autonomous rotarywing unmanned aerial vehicle in a cluttered environment. The model predictive control combined with a potential fieldlike function integrates planning and control in a single step. This strategy enables the generation of dynamically feasible motion because the planning is done in the action space of the rotary-wing unmanned aerial vehicle. Moreover, it is able to respond promptly to abrupt changes in the environment because the reactive obstacleavoidance method only considers local sensory information. Finally, the shortsightedness of control-based reactive methods can be relieved by the larger planning horizon of the model predictive control. Simulation results show that the proposed integrated planning and controlmethod can complete the navigationmission successfully in a cluttered environment, and it can be applicable to more complicated missions, such as weed surveillance and management.

Reńe H. Miller (May 19, 1916–January 28, 2003), Emeritus H. N. Slater Professor of Flight Transportation at the Massachusetts Institute of Technology, was one of the most influential pioneers in rotary wing aeromechanics as well as a visionary whose dream was the development of a tilt-wing/tilt-rotor–based, short-haul air transportation system. This paper pays a long overdue tribute to his memory and to his extraordinary contributions.

A compressible Reynolds-averaged Navier–Stokes (RANS) solver is used to improve the design of a microscale shroud applicable for micro air vehicle (MAV) applications. The new shroud is primarily designed to improve the hover performance; however, it is also shaped to better suit nonhovering flight conditions. The proposed shroud design has an elliptic shape on the inner portion of the shroud inlet and a circular shape on the outer portion. A collective angle sweep study of the shrouded rotor configuration using the proposed shroud design shows significant performance benefits in hover.

The pararotor is a biology-inspired decelerator device based on the autorotation of a rotary wing, whose main purpose is to guide a load descent into a certain planetary atmosphere. This paper focuses on a practical approach to the general dynamic stability of a pararotor whose center of mass is displaced from the blade plane. The numerical simulation tool developed is based upon the motion equations of pararotor flight, utilizing a number of simplifying hypotheses that allow the most influencing factors on flight behavior to be determined. Several simulated cases are analyzed to study the effect of different parameters associated with the pararotor configuration on flight dynamics, particularly the center of mass displacement from the blade plane. It was confirmed that the ability to reach stability conditions depends mainly on a limited number of parameters associated with the pararotor configuration: the relationship between principal moments of inertia, the planform shape (associated with blade aerodynamic coefficients and blade area) and the vertical distance between the center of mass and the blade plane. As a result different types of equilibrium solutions are found and the effect of each parameter is characterized. A bifurcation in the stability shape to a precessing conical rotation, not previously found in the linear stability analysis, is predicted by this numerical model., Facultad de Ingeniería

The length of line to steady the stretcher, as 60 m is confirmed. If required the product pamphlet of the manufacturer can be obtained from the author. The usage of the stretchers described, will necessarily be influenced by the air evacuation asset being used. Cheetahs the light utility helicopters developed from the Alouette II, the lama have demonstrated their capabilities as a rescue machines though they are not primarily meant for an air ambulance role. The stretcher for casualty evacuation is to be placed longitudinally after removing the co-pilots seat and rudder on the port side. However since single pilot flying is not permitted, the stretcher could be slung underneath in either horizontal or vertical axis of the aircraft to enable a “sit down”. Since in flight care like suction/oxygen, intravenous fluid/drug administration is often required to be continued by the attendant, “external: air evacuation should be done only when inescapable. Besides for a conscious patient a ride outside the aircraft in high altitude could be very unnerving! Limitations of stretcher maneuverability will always be there, unless a rotary wing asset is specifically designed for rescue and air ambulance role. Inspite of structural inadequacies of the Cheetah helicopter for casualty air evacuation they have been used for the same from high altitude posts. They are also being used for air transfers in emergency situations from one medical echelon to another in the passenger section of the cockpit/cabin, without stretchers for want of better alternative. Experience of a forward medical unit which air evacuated 132 patients mostly battle casualties post operatively, on cheetahs to rearward medical echelon entitled. “An Appreciation of Casualty Air Evacuation from 328 Field Ambulance” is available with the author

In this paper, a distributed guidance law is proposed for multiple rotary-wing unmanned aerial vehicles (UAVs) to intercept multiple intruding targets. The proposed distributed guidance law is based on integrated parallel navigation and pure pursuit. Potential functions are applied to avoid inter-agent collisions and mis-interceptions. The main distinct features of the proposed distributed guidance law include: 1) it does not rely on the theory of consensus; and 2) the strategy of collision avoidance is orientation-based (instead of distance-based or position-based). It can be proved theoretically that, with the proposed distributed guidance law, each UAV is capable of intercepting its target with finite time and non-zero hitting velocity, and there exist neither inter-agent collisions nor mis-interceptions before interceptions. Theoretical results are illustrated by a simulation example.

This work demonstrates the application of Unmanned Aerial Vehicles (UAVs) in a robotic Urban Search and Rescue (USAR) mission. An intuitive and natural control methodology that can be universally applied to different types of unmanned rotary wing aerial vehicles is developed. The control system encompasses a Windows computer system and a 3-Dimensional depth-sensing camera, in particular the Microsoft Kinect. Human hand gestures are captured, filtered and translated into flight manoeuvres for the UAV. The filtering involves the application of Fuzzy Logic Controllers, which incorporate the use of several different input variables for the control of either the velocity or position of the UAV. The developed system is implemented and tested on an AR Drone.

BAE Systems two-part Striker helmet product family is a mature fully integrated helmet mounted display in volume production and used on multiple fixed wing and rotary wing platforms worldwide. The Striker system on Typhoon and Gripen provides a high accuracy off bore sight weapon cueing capability to the fast jet users in eight nations. The advanced all digital rotary wing variant of the Striker HMD is a dedicated helicopter variant which has already been extensively flight tested in U.S., UK, and European platforms. This visor-projected HMD is a mature, advanced integrated display helmet that has been specifically designed for high capability military HMD applications but also has a wider dual use capability in specialist non-military applications. The underlying two-part integrated helmet concept is also a mature design already in wide spread operational use. The combination of these features has enabled the core Striker HMD design concept to be enhanced to meet the demand of both 5th Generation fixed wing platforms and enhanced capabilities for future military and civil rotary wing applications.

Search and Rescue (SAR) is an operation conducted to find and return to safety the survivors of an emergency incident, where the search may have to be conducted in difficult areas such as in mountains, deserts, forests or at sea. Maritime SAR operations normally involve a large number of vessels and possibly helicopters as well, but this has been found not to be effective enough. This paper looks at Unmanned Aerial Vehicles (UAVs) to assist in maritime SAR operations, leaning towards rotary wing UAVs with the capabilities of flying vertically and horizontally as well as hover at required positions for close monitoring. The focus is on the algorithm for determining the exact position of the target subject(s).

The consideration of safety issues in the operation of helicopters involves the capability to perform emergency descending maneuvers through the autorotation principle when the engine is no longer supplying power. When comparing manned and unmanned helicopters, the lower rotor inertia of UAV configurations makes this functionality even more challenging for the pilot since more accurate timing and speed control of the flare phase are required. This paper presents a complete set of guidelines to design a controller for the autonomous autorotation landing of an UAV. This analysis is based on experimental data that corresponds to autorotation landings of a small-size helicopter carried out by a skillful pilot.

There are five classes of locomotion adopted in mobile robots that are applicable to planetary exploration rovers: (i) wheels—rolling (e.g., automobile locomotion); (ii) tracks—rolling/screwing (e.g., armored vehicle locomotion, rotary drill); (iii) legs—walking (e.g., animal locomotion); (iv) body articulation—crawling/sliding (e.g., snake undulation); (v) non-contact locomotion—hopping/flying.

In its effort to develop unmanned autonomous systems research capabilities, the college of engineering is adding a rotary wing UAV to its research activities. This paper demonstrates the use of Maxi Joker 3 commercial-off-the-shelf (COTS) electric RC helicopter as a platform and implementing it with COTS autopilot system to serve as a benchmark for future AUS rotary wing in-house autopilot development. Many problems and issues were experienced during the flights, such us mechanical vibrations, acoustic noise, and autopilot failure during the flight and consequently crashing the platform. All of those problems were solved inside the lab on a test stand which was designed to fly and test the helicopter avoiding crashing and without a skilled pilot sometimes.

Fretting fatigue has become one of the most significantly recognized failure mechanisms in engineering applications of critical components of many joined sub-systems or systems. It is one of the major areas of concern in fixed wing aircraft connections, rotary wing gearboxes, clutches, bearings, bushing, lugs, and engines of all types in the aviation industry. For many years the power generation industry has recognized the importance of fretting fatigue and some major failures have been attributed to fretting fatigue over many years. It has been of concern in many other industries in recent years. As the knowledge on fretting corrosion, fretting wear, and fretting fatigue has expanded it has been recognized as a major source of the failure of engineering components in a myriad of applications. This has led to recent standards for testing and terminology related to fretting fatigue in Japan, the USA/Canada (ASTM), and France.

The goal of the paper is to propose a new type of ornithopter that avoids the mechanical difficulties of a flapping system. It uses a modified design of a cycloidal propulsor. The modification regards the special setting of the wings that is intended to help the formation of a stable leading edge vortex (LEV). It is known that the LEV is the main feature that allows the insects to achieve the necessary lift to fly.

The aim of the current study was to evaluate the utility of three flight simulator motion conditions (fixed-base, motion-cueing seat, and full-motion) to support training of in-flight rotary-wing emergency recovery procedures. Military helicopter pilots were randomly assigned to two of three possible motion configurations and subject to three in-flight emergencies. Pilot handling ratings indicate wide acceptance of the training device in each of the three configurations. Subjective workload assessments showed no difference between motion configurations. Results will be discussed with reference to the importance of pilot simulator acceptance during flight training.

The purpose of this study is to develop a twin wheel creep-feed grinding machine using continuous dressing to machine precise axisymmetric turbine blades that have been difficult to machine using a conventional creep-feed machine. In order to develop such a machine, 3D-modeling and machine simulations were performed and a twin wheel creep-feed grinding machine was manufactured. Furthermore, the axisymmetric precision of the machined workpieces through practical machining was evaluated and the quality of the continuous dressing effect of the developed machine was established. In addition, experimental considerations for a proper dresser-to-wheel speed ratio and proper feed rate of the dresser were carried out. As a result, a twin wheel creep-feed grinding machine with continuous dressing is developed through machine simulation, manufacturing and performance evaluation. Optimum condition for the dresser feed rate is 0.3 μm/rev. In cases of large dressor-to-wheel speed ratio, grinding efficiency can be enhanced, but the surface roughness shows a conflicting trend. Developed twin wheel creep-feed grinding machine has satisfactory appraisal with regard to surface roughness, flatness, and parallelism. Satisfactory surface roughness below 0.1 μm can be obtained for the blade of aircraft. However, in order to perform precise machining, it is necessary to improve the structure of the twin wheel creep-feed grinding machine.

The HART II test of 2001 provided a significant and comprehensive database of rotor loads, blade motion, blade pressure distribution, acoustic signature and flow field data. A sub-set of these were released for public access worldwide and an International HART II Workshop was established in 2005. This Workshop, open to the international rotorcraft community, has been held since then at both the AHS Annual Forum as well as the European Rotorcraft Forum. Following the requests of participants, the HART II International Workshop database has been undergoing continuous development. This paper describes the current content and status of the data and the documentation material provided within the workshop database.

summary With the development of highly sophisticated tertiary care facilities, the need to move critical care patients between hospitals is becoming an increasing common phenomenon. In many areas the distances involved in these transfers and the urgency of the cases has led to the use of aerial transport of retrieval teams and their patients. This article discusses the physiology of aeromedical transport and its effects on certain clinical conditions and the equipment used. The article also offers some practical advice on personnel, equipment and how to carry out a tasking in both fixed wing and rotary wing aircraft.

This paper presents a novel compensation method for the coupled fuselage-rotor mode of a Rotary wing Unmanned Aerial Vehicle (RUAV). The presence of stabilizer bar limits the performance of attitude control of an RUAV. In this paper, a Positive Position Feedback (PPF) is introduced to increase the stability margins and allow higher control bandwidth. The identified model is used to design a PPF controller to mitigate the presence of stabilizer bar. Parameters for the linear RUAV model are obtained by performing linear system identification about a few selected points. This identification process gives complete RUAV dynamics and is suitable for designing a Stability Augmentation System (SAS) of an RUAV. The identified parameters of an RUAV model are verified using experimental flight data and can be used to obtain the nonlinear model of an RUAV. The performance of the proposed algorithm is tested using a high-fidelity RUAV simulation model, which is validated through experimental flight data. The closed-loop response of the rotorcraft indicates that the desired attitude performance is achieved while ensuring that the coupled fuselage-rotor mode is effectively compensated without penalizing the phase response.