Ultrasonic guided waves are used to detect the delamination between skin and honeycomb of a composite helicopter rotor blade. Theoretical work is carried out for guided waves in the trailing edge of a rotor blade, which is a multilayer composite skin/NOMEX half space structure. The dispersion relation is obtained with the global matrix method. Theoretically driven experiments are conducted on a...

A helicopter is not possessed of an ability to fly fast compared with fixed-wing counterparts. This is a result of considerations with the main rotor. The main rotor moves in a direction very close to its plane of rotation which naturally divides it into two halves which operate under different aerodynamic conditions. One side (called the advancing side) has the rotation and translation velocit...

The paper is focused on the development of algorithms for motion planning of an autonomous helicopter in a GPS-denied environment. Methods for determining the location of the helicopter, during the flight, are presented. The methodology is based on a lightweight laser range finder as a sole onboard sensor. The sensor reading interpretation are combined with various path planning algorithms acco...

in the present paper, the aeroelastic stability of helicopter rotor blade is determined using aeroelastic frequency response function. the aeroelastic model of blade is obtained by combining dowell - hodges beam model with loewy unsteady aerodynamic theory which considers an unsteady wake beneath the rotor. equations are formed and aeroelastic frequency response functions are obtained by invert...

In this paper, twin rotor multi input multi output system (TRMS) is considered as a prototype laboratory set-up of helicopter. The aim of studying the model of TRMS and designing the controller for it is to provide a platform for controlling the flight of helicopter. An optimal state feedback controller based on linear quadratic regulator (LQR) technique has been designed for twin rotor multi i...

A novel wavelet-based sparse signal representation technique is used to separate the main and tail rotor blade components of a helicopter from the composite radar returns. The received signal consists of returns from the rotating main and tail rotor blades, the helicopter body, possible land or sea clutter, and other residual components, which may all overlap in time and frequency; and therefor...

This paper focuses on a critical component of the situational awareness (SA), the control of autonomous vertical flight for tactical unmanned aerial vehicle (TUAV). With the SA strategy, we proposed a two stage flight control procedure using two autonomous control subsystems to address the dynamics variation and performance requirement difference in initial and final stages of flight trajectory...

On the cover: Representation of the flow around a helicopter blade with a Gurney flap. Summary Today's helicopters are the result of collaborative work in mechanical engineering and aeronautics. The European project " Clean Sky " aims at improving the efficiency and the global transport quality of aircraft. In the field of rotorcraft, the research in this project is currently focussing on activ...

In this study we investigated the possibility of increasing the visibility of helicopter rotor tips when viewed from the underside. In an experimental study we used a model of a rotor blade spinning at a fast enough rate that it appeared as a transparent disk. The tips of the blades were painted fluorescent red-orange, and were observed under three different lighting conditions. In one conditio...

This paper addresses the feasibility of using trailing edge flaps to reconfigure a helicopter rotor blade following a failure of the pitch link, which makes the blade freefloating in pitch and otherwise uncontrollable. A coupled rotor-fuselage model is developed which allowed for rotor anisotropy. A new, optimization-based, trim procedure is developed to determine the dynamics of the failed bla...