This paper provides a parametric study to obtain the optimal wing rotation angle for the generation of maximum transla- tional force in an insect-mimicking Flapping-Wing Micro Air Vehicle （FWMAV） during hovering. Th...This paper provides a parametric study to obtain the optimal wing rotation angle for the generation of maximum transla- tional force in an insect-mimicking Flapping-Wing Micro Air Vehicle （FWMAV） during hovering. The blade element theory and momentum theory were combined to obtain the equation from which the translational aerodynamic force could be esti- mated. This equation was converted into a non-dimensional form, so that the effect of normalized parameters on the thrust coefficient could be analyzed. The research showed that the thrust coefficient for a given wing section depends on two factors, the rotation angle of the wing section and the ratio of the chord to the travel distance of the wing section in one flapping cycle. For each ratio that we investigated, we could arrive at an optimal rotation angle corresponding to a maximum thrust coefficient. This study may be able to provide guidance for the FWMAV design.展开更多
An adaptive beamforming algorithm named robust joint iterative optimizationdirection adaptive （RJIO-DA） is proposed for large-array scenarios. Based on the framework of minimum variance distortionless response （MVD...An adaptive beamforming algorithm named robust joint iterative optimizationdirection adaptive （RJIO-DA） is proposed for large-array scenarios. Based on the framework of minimum variance distortionless response （MVDR）, the proposed algorithm jointly updates a transforming matrix and a reduced-rank filter. Each column of the transforming matrix is treated as an independent direction vector and updates the weight values of each dimension within a subspace. In addition, the direction vector rotation improves the performance of the algorithm by reducing the uncertainties due to the direction error. Simulation results show that the RJIO-DA algorithm has lower complexity and faster convergence than other conventional reduced-rank algorithms.展开更多
文摘This paper provides a parametric study to obtain the optimal wing rotation angle for the generation of maximum transla- tional force in an insect-mimicking Flapping-Wing Micro Air Vehicle （FWMAV） during hovering. The blade element theory and momentum theory were combined to obtain the equation from which the translational aerodynamic force could be esti- mated. This equation was converted into a non-dimensional form, so that the effect of normalized parameters on the thrust coefficient could be analyzed. The research showed that the thrust coefficient for a given wing section depends on two factors, the rotation angle of the wing section and the ratio of the chord to the travel distance of the wing section in one flapping cycle. For each ratio that we investigated, we could arrive at an optimal rotation angle corresponding to a maximum thrust coefficient. This study may be able to provide guidance for the FWMAV design.
基金supported by the National Science&Technology Pillar Program(2013BAF07B03)Zhejiang Provincial Natural Science Foundation of China(LY13F010009)
文摘An adaptive beamforming algorithm named robust joint iterative optimizationdirection adaptive （RJIO-DA） is proposed for large-array scenarios. Based on the framework of minimum variance distortionless response （MVDR）, the proposed algorithm jointly updates a transforming matrix and a reduced-rank filter. Each column of the transforming matrix is treated as an independent direction vector and updates the weight values of each dimension within a subspace. In addition, the direction vector rotation improves the performance of the algorithm by reducing the uncertainties due to the direction error. Simulation results show that the RJIO-DA algorithm has lower complexity and faster convergence than other conventional reduced-rank algorithms.
