Helicopter stability and control in the presence of windshear

Abstract

PurposeThis paper aims to present a theoretical method for analyzing the stability and control of a hingeless helicopter in the presence of windshear.Design/methodology/approachIn this paper, the stability and control of a hingeless helicopter in the presence of windshear are investigated. First, the rotary wing dynamic model considered is the one of flap‐pitch (including the elastic deformation of the control system)‐torsion coupling. The induced velocity nonuniform distribution derived from vortex theory is taken into account. Then, as for atmospheric turbulence, the linear windshear model is used for modeling the variation of wind field. Finally, according to the calculated results of the stability characteristic roots and the control response of the helicopter, the helicopter performance in wind shear field is analyzed, and some conclusions are obtained.FindingsSome useful conclusions are obtained through sample analysis.Research limitations/implicationsAlthough the analyses for stability and control of a hingeless helicopter in the presence of windshear could be obtained using the current method, the model of complex wind field will still be expected in future studies.Practical implicationsA very useful method for analyzing helicopter stability and control.Originality/valueThe proposed method is valid and available for the analysis of helicopter flight dynamics.

Gust loads on aircraft

“…One group of the current authors, Cao et al investigated the influence of wind shear on both helicopter flight characteristics (176,177) . It was found that left wind, tail wind and downdraft decrease the longitudinal stability, while the left wind, right wind and downdraft decrease the lateral/directional stability, as shown in Fig.…”

Direct adaptive fuzzy control for a nonlinear helicopter system

“…On the other hand, nonlinear dynamics simulation, stability and control problems in helicopter design have been studied in Cao et al (2004) and Su et al (2007). Newman (2006) investigated the design characteristics of helicopters address to the requirements of efficiency in operations.…”