| Bio-inspired flapping wing micro aerial vehicles(FWMAV)is a kind of air-flying robot that achieve flight through flapping wings like creatures.Because of its future broad application prospects in the field of military and civilian,FWMAV has become a hot research topic in aviation science in recent years.In this paper,the aerodynamic characteristics and optimization design of wings of FWMAV are studied.It includes the following aspects:Firstly,the flapping-wings flight mechanism of flying creatures was analyzed and its high-lift mechanism was qualitatively explained.Then the morphology of wing and the flapping kinematics are described,which the kinematic expressions of flapping wings are given by the rotation matrix.By deriving a quasi-steady aerodynamic model,the aerodynamic forces and moments generated by flapping wings are obtained from aerodynamic loads analysis.Based on the aerodynamic model,an energy consumption of flapping-wings model was established.The theoretical basis of wing design and aerodynamic characteristics analysis was built by combining the two models.Secondly,based on aerodynamics of flapping-wings,a wing design model was established,which including the wing geometric design,kinematic design,and wing ribs design,thereby a complete wing design model was obtained through design parameterization.According to the wing design theory,the corresponding experimental wing manufacturing scheme was determined,and the flapping wing experimental mechanism was selected and a pneumatic experimental platform suitable for FWMAV was established.Therefore,the aerodynamic force,torque and energy consumption can be obtained through experiments.Thirdly,in order to improve the aerodynamic performance of the FWMAV in hover flight,several optimized designs for the wings were performed.Based on the aerodynamic analysis and experimental results,a significant analysis of the aerodynamic characteristics of the wing design parameters is performed.The design parameters with significant influence were selected and determined as design variables in the optimization design.By using the aerodynamic force required to achieve hover flight as a design constraint,the wing was optimized based on the goal of high energy efficiency,and the energy efficient wing design was obtained.The hover flight performance of flapping wing was further analyzed based on the results of high energy efficiency optimization.The results showed that although the flapping wing energy consumption was significantly reduced,the actual hover performance was not perfect.Therefore,a lift difference function that affects the stability of hovering flight is established,and it is used as one of the optimization targets for multi-objective optimization design of the wing.Then the particle swarm multi-objective algorithm is used to solve the problem,a wing design with high energy efficiency and high stability is obtained.Finally,the energy consumption of FWMAV during operations is quantitatively analyzed,and an all energy consumption model of FWMAV operations is established.Taking the input power that drives FWMAV to complete the flight as the basis,it is decomposed into three parts: the power of flapping wing,the power loss in heat and the power to drive mechanism,and the experimental data is used for modeling.The energy consumption model of flapping wing is based on the original aerodynamic energy consumption model,which is improved by add two energy compensation coefficients.The energy compensation coefficients are solved and revised based on the experimental results.Next,the optimization design of the wing was performed using the all energy consumption model.The wing optimization results under the all energy consumption model were obtained and the energy distribution analysis was performed.The results show that the optimization design results based on the all energy consumption model have lower energy consumption requirements in actual operation and have better practical application value. |
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