An Autonomous Inspection System For Wind Turbine Blade Based On Unmanned Aerial Vehicle

In recent years,in China,wind power industry has been developing continuously,and the scale of wind farms has been continuously expanding,so the traditional manual inspection method has been unable to meet the safety and efficiency of wind turbine inspection.With the development of UAV(Unmanned Aerial Vehicle)technology,the application of UAV in the field of patrol inspection will have high practical value,and it is also a hot research topic at home and abroad.In this paper,an autonomous inspection system based on a four-rotor UAV is proposed and implemented for wind turbine blade.The core innovation of the autonomous inspection system is to design and implement a visual measurement algorithm to locate the patrol and inspection target.The positioning accuracy and stability of the visual measurement algorithm guarantee the reliability and efficiency of the system.In addition,the structural characteristics of wind turbines are analyzed,and a specific route planning scheme is designed.The kernel contents include as follows:1)Combined with the special operation scenarios of wind farms,the characteristics of UAV operation in special environment are studied,the design scheme of the autonomous inspection system is presented,and the system is divided into two parts: UAV and ground station software.On this basis,it summarizes the requirements of hardware configuration in the system design process,analyzes the appropriate hardware configuration selection,and explains the relevant pre-processing operations.2)Analyzing the principle of navigation related coordinate system and the transformation of the relationship between each other,according to the camera imaging principle,combined with GPS information and pixel coordinates information,design and implement a kind of algorithm,which is used to locate the visual measurement.Just by taking a few aerial photos of the target,the photo information can be used to calculate the geographic coordinates of the target to be inspected.3)According to whether the structural information of the wind turbine is known,the convenience of wind turbine modeling in different scenarios is analyzed.In combination with the design principle of visual measurement algorithm,the corresponding route planning scheme is designed to ensure the reliability of the inspection.4)In view of the stability of the visual measurement algorithm,several different experiments were designed and tested with the designed software.Summarize and analyze the experimental results,exclude some possible influencing factors,and obtain the qualitative influence of aerial photography Angle and aerial photography distance on the patrol inspection.5)According to the characteristics of the fan inspection,several experiments are designed to estimate the accuracy of the visual measurement algorithm,so as to ensure the accuracy meets the safety requirements of the autonomous inspection and ensure the feasibility of the autonomous inspection system.Finally,by analyzing and summarizing the data of multiple experiments,it is concluded that the positioning accuracy of the visual measurement algorithm can reach the centimeter level,which fully meets the accuracy requirements of the autonomous patrol inspection.