Research On Anti-disturbance Performance Of Adaptive Aerodynamic Shape For Hovering Micro Air Vehicle

Due to the fact that micro air vehicles have small-scale, low weight, low inertia,small Reynolds number and low flight speed, their flight stability is more sensitive towind gust as well as complex atmosphere flow. However, currently the analytical andcomputational approach about disturbance rejection technology has not beencompletely established. Based on the detailed study of anti-disturbance aerodynamicdesign and self-adaptive aerodynamic characteristics of micro air vehicles, the thesishas proposed a hovering flying model with a flexible aerodynamic shape. Theanti-disturbance performance of its flexible aerodynamic shape has been discussedand implemented by numerical simulation, experimental study and theoreticalderivation respectively, which is a significant contribution to the flexible aerodynamiclayout design of hovering flying vehicles in the future.The major research contents and innovations of the thesis are summarized asfollows:The FEM numerical analysis based on a multi-field information transmission andfluid-structure interaction has been utilized to calculate the unsteady aerodynamiccharacteristics. Through the comparative trials of flexible aerodynamic shape andrigid aerodynamic shape, in which both research models have the same layout designand structural parameters, the differences in terms of flow field distribution, adaptiveelastic deformation and aerodynamic forces have been found. It has been showed thatthe hovering flying model with a flexible aerodynamic layout has better aerodynamiccharacteristics and flight performance. The Lagrange equation of motion has beeninvestigated and based on this the method of improving the flight performance isproposed. In order to find the most significant influence factors and the optimaldesigned aerodynamic layout, an orthogonal experimental design and related analysisare presented.The experimental prototype of the hovering flying object with a flexibleaerodynamic shape and the experimental environment with simulation and detectionfunctions have been built. Instead of using high frame rate imaging equipment, theproposed3D visualization detection method is based on a stroboscopic imagingtechnique to record the information of the flexible aerodynamic shape. The scale invariant feature transform (SIFT) features are extracted from left and rightstroboscopic images to realize space information acquisition. The flexibleaerodynamic shape is represented by triangle mesh subdivision algorithm usingextracted SIFT features as control vertex. Given system error analysis andcorresponding solutions, the experimental measurement for anti-disturbanceperformance of the flying prototype is completed in the thesis to acquirethree-dimensional information of its flexible aerodynamic shape in terms of kineticparameters, morphology structure and elastic deformation.Based on various aerodynamic layout designs of the hovering flying object, amathematical surface model of the aerodynamic shape has been established. Theapproach to improving the flight stability of the flying model has been analysed.Combined with subdivision surface resulted from the aerodynamic shape’s3Dvisualization measurement, the relationship between aerodynamic layout andinfluence factors on the stability performance has been constructed. Theanti-disturbance mechanism of the hovering flying model is deduced to providereferences for the improvement of flight stability and the enhancement ofanti-disturbance performance during the hovering flying model’s design process.