| Rotary-wing UAVs(Unmanned Aerial Vehicle)are frequently used in the domains of natural disaster reconnaissance,terrain surveying,and civil aerial photography because of their simple structure and flexible operation.Due of the UAV’s restricted range,it is important to return to the assigned point for battery change in marine monitoring.However,the landing plane at sea is not in a smooth state,and the safe landing of the UAV cannot be achieved by relying only on GPS navigation and inertial navigation units.Therefore,autonomous landing of UAVs for dynamic planes becomes an urgent problem.To solve this problem,this paper proposes an autonomous UAV landing scheme combining machine vision and landing plane attitude autonomy feedback,and carries out the following theoretical analysis and experimental research work for practical working requirements.Firstly,the technical solutions for autonomous landing of UAVs at home and abroad are analyzed,the limitations of its use range and safety performance are described.The effect and robustness of sensor data fusion used in UAVs are deeply studied.Secondly,to address the current technical difficulties,an autonomous landing scheme for UAVs based on landing plane attitude autonomy feedback is proposed,and the control platform is built according to the performance of hardware devices.A nested landing signs are designed based on Aprlitag to meet the requirements of machine vision recognition,and its dimension is experimentally determined.Then,a theoretical analysis of the UAV flight principle as well as the control of attitude and position is performed using a quadrotor UAV as an example.Multi-sensor data fusion is performed using Kalman filter for the altitude measurement aspect of the UAV to improve the accuracy of the data information.A mathematical model of the UAV control system is established and simulation experiments are conducted to verify the accuracy of its flight control.Finally,the machine vision part of the program design and hardware construction of the utilized YoloV5 and OpenMV are combined with the designed landing plane detection system for dynamic plane tracking and landing experiments,and the results show that the landing scheme can improve the success rate of the UAV on the dynamic plane. |
