The research on helicopter rotor aerodynamic noise becomes imperative with the wide use of helicopters in civilian fields. In this study, a signal enhancement method based cyclic Wiener filtering was proposed given cyclostationarity noise. adaptively filtered out by performing group frequency shifts input signal. According to characteristics noise, detection function constructed realize long-di...

This article highlights the significance of rotor dynamics in control design for small-scale aerobatic helicopters and proposes two singularity-free robust attitude-tracking controllers based on available states feedback. The first employs angular velocity flap angle (a variable that is not easy to measure) uses a backstepping technique compensator (BRC) actively suppress disturbance induced tr...

This paper presents a passive bistatic radar (PBR) configuration using global navigation satellite system as an illuminator of opportunity for the rotor blade feature extraction helicopter. Aiming at strong fixed clutter in surveillance channel PBR, novel iteration elimination method-based singular-value decomposition approach is proposed. Instead range method used classic extended cancellation...

The majority of research into full-sized helicopter overlapping propulsion systems involves co-axial setups (fully overlapped). Partially overlapping rotor setups (tandem, multirotor) have received less attention, and empirical data produced over the years is limited. The increase in demand for compact small unmanned aircraft has exposed the need for empirical investigations of overlapping prop...

In this paper the design, fabrication and analysis of behavior by full-scale ver-ification testing for the tail rotor blade of composite laminated materials for a heavy transport helicopter is given. The verification test program for the tail rotor blade encompassed static and dynamic test-ing. The static tests of the blade involved experimental evaluation of torsional and flexional blade stif...

The aim of this work is to design the system for autonomous stabilization of a formation of multi-rotor helicopters for the cooperative Ąlming in dark conditions. The leader-follower approach and the model predictive control on receding horizon are applied for this purpose. The formation consists of one multi-rotor helicopter carrying a camera and the arbitrary number of multi-rotors carrying l...

This paper presents a study on the effect of wake modeling on the prediction of the off-axis response to pilot inputs for a hingeless and an articulated rotor helicopter, including a comparison with flight test data. The free wake model can capture geometry changes due to maneuvering flight. The prediction of the response to pilot inputs improves only slightly; in particular, the off-axis respo...

This paper presents a set of optimizations in learning algorithms commonly used for training radial basis function neural networks. These optimizations are applied to a RBF neural network used in identifying helicopter types processing their rotor sounds. The first method uses an optimum learning rate in each iteration of train process. This method increases the speed of learning process and al...

A variable camber morphing rotor blade with curvilinear fiber composite skin is studied in this paper. The benefits of curvilinear fiber (CVF) composites for morphing skin over the linear fiber are investigated, initially. The skin of a morphing blade is modeled as a plate supported between the D-spar and trailing edge of typical rotor blade dimensions. The CVF composite shows about 60 % increa...