Design And Control Of A Camera Stabilizer For Bionic Flapping-wing Robotic Bird

The Bionic Flapping-wing robotic Bird has the characteristics of good flight performance,strong flexibility and high hidden appearance.It can be widely used in military investigation,environmental survey and life rescue.In order to achieve the above functions,the bionic flapping-wing aircraft needs to have visual surveillance functions.Since the center of gravity and attitude of the flapping-wing aircraft are difficult to maintain stable,it is difficult to provide stable aerial photograthy conditions for the camera,and the limited size and load capacity of the existing flapping-wing aircraft also brought challenge for the visual surveillance development of flapping-wing aircraft.By analyzing the structural parameters and flight characteristics of the bionic flapping-wing aircraft,the design scheme of the flapping-wing aircraft camera stabilizer is proposed.By taking the flapping-wing robotic bird HIT-Phoenix as the research carrier,the experiment of the attitude change during flight was carried out,and the requirements of the camera stabilizer was carried out according to the flight characteristics and the related components was selected to make the machanical design.The camera stabilizer has 2 DOF of rotation and 1 DOF of displacement,which can compensate the camera's attitude deviation by rotational freedom,and can complete the overall expansion and contraction by displacement.It has a compact structure and is suitable for flapping-wing flight conditions..Based on the design of the camera stabilizer,the kinematic calculation was carried out,and an attitude calculation method was proposed.The coordinate system of the camera stabilizer was established,and the relationship between attitude and speed of the flapping-wing body and the camera stabilizer was determined by calculation.According to the measured data of the attitude sensor,the Euler angle was obtained by combining the data of accelerometer and the gyroscope.The motion acceleration of the camera is corrected by the fuselage IMU,which effectively eliminates the motion acceleration interference of flpping-wing flight and reduces the attitude calculation error.According to the requirements of the camera stabilizer,the control system was designed and a motor drive method was proposed.The function of the camera stabilizer was analyzed.The control circuit and control board of the system is designed.Based on the control board,the control process was programmed,and the SPWM wave is used to drive and control the motor.The control system takes the functions required for the camera stabilizer into consideration,and has the characteristics of high integration and good stability.A prototype of the camera stabilizer was developed and the experiment was carrid out.Comparing the attitude change between the camera and the robotic bird,the stabilization effect was verified.The program is designed to test the response of the camera stabilizer to the abrupt step signal and thee response speed was obtained.Finally,the bionic flapping-wing robotic bird equipped with the camera stabilizer was used for flight test,and the picture was compared with the camera alone picture to observe the stabilization effect and overall motion performance of the camera stabilizer.Experiments have shown that the camera stabilizer meets the design requirements.