Research On Tail Aerodynamics And Control Technology Of Bird-like Flapping-wing Aircraft

Aiming at the aerodynamics and control of the tail wing of a bird-like flapping wing aircraft during flight,the movement characteristics of the pigeon’s tail wing under different flight conditions are obtained.Analyzi the aerodynamic principle of bird tail wing,the concept of flexible deformation is introduced and a two-degree-of-freedom dynamic model of the flexible tail is established.The simulation and the experiment is used to analyze the aerodynamic characteristics of the tail.The dynamic model is used to establish an incremental PID control equation for the state angle of the tail.The control structure is designed and tested,consisting of the microcomputer and other components.The motion characteristics of the tail under different flight conditions obtained by high-speed photography.Compare the characteristics of the tails of different aircrafts to analyze the aerodynamic principles of bird tail surfaces in flight.According to the characteristics of the flexible deformation of bird feathers during the incoming flow,the concept of flexible deformation degree is proposed to measure the degree of flexible deformation of the material.The empennage dynamics model makes theoretical calculations and analyzes the results of the theoretical calculations.Three types of tail are designed,and the simulation is used to calculate the tail surface with different states.The aerodynamic characteristics of different-shaped tail surfaces are analyzed.Comparing the calculation results of fan-shaped tail,triangle-shaped tail and dovetail-shaped tail,it is proved that the designed fan-shaped tail has the best aerodynamic characteristics during flight.The force and flow field state of the airfoil under the action of incoming flow are obtained by experiment,and compared with the results of theoretical calculation and numerical simulation,the effectiveness of the established model is verified.Using the established dynamic model to study the control process of the rear wing,the control equations of the flapping angle of the rear wing and the rolling angle of the rear wing are obtained.Based on the PID control principle and the critical scaling method.The tail state angle control process uses a microcomputer as the core and is supplemented by a steering gear and a six-axis sensor.The results collected by the sensor are filtered and solved using Kalman filtering.The measured results verify the feasibility of the designed tail state angle control process.