Design And Implementation Of A Low Cost Small UAV Image Intelligent Acquisition System

With the continuous development of science and technology,UAV systems have gradually integrated into all aspects of social development and become indispensable civilian and military equipment.Unmanned aerial vehicle technology,as a technical means to obtain ground information in a timely and effective manner,has already been widely used in the fields of land resources,energy,commerce,agriculture,police,medical treatment,and disaster prevention and mitigation.At present,commercial aerial survey drones have high purchase and maintenance costs,long maintenance periods,and system closures,which have resulted in high purchase risks and high input-output ratios for enterprises.Therefore,based on the Pixhawk open-source flight control system,this article develops a low-cost UAV image intelligent acquisition system with high positioning accuracy and data sharing.This system can meet the needs of foreign industry in the field of national land investigation.The surveying,mapping and remote sensing system for light and small UAVs consists of sensors,flight platforms,flight control systems,ground monitoring systems,and remote control and telemetry links.This article addresses the problem of low efficiency of drone collection and management data,this paper uses the Micro Air Vehicle Link protocol to realize the serial communication between UAV and ground station,and controls the two to work together to complete data collection.Use the Pixhawk flight control system control signal to design and complete the image acquisition module,and use the NEO-M8 T low-cost GNSS receiver to construct a differential measurement system to improve the positioning accuracy of the UAV.Finally,upload the image and coordinate data obtained by the drone to the data management system to realize the intelligent collection and management of data.The research results obtained are as follows:(1)Researched and developed and built the drone airborne platform.In view of the requirements for the collection of aerial photography images of the UAV,the main design parameters and control system of the quadrotor UAV were first determined,and the corresponding hardware was selected to realize the construction of the UAV airborne platform to ensure the flexibility and stability of the system.Then the multi-rotor UAV airborne platform was tested by the xcopter Calc evaluation software and actual flight,and the results show that the layout of the airborne platform is reasonable and the stability is good.(2)Design and realize the synchronous collection of aerial photographic images and GNSS receiver data.According to the Pixhawk flight control system control signal format and the camera shutter trigger principle,the camera shutter exposure and data synchronization acquisition method of the GNSS receiver module are designed.The MAVLink communication protocol is used to transmit shooting commands,the camera shutter exposure is triggered and the positioning data of the GNSS receiver is obtained at the same time,and finally the synchronous acquisition of image data and POS data is completed.(3)Through the combined differential positioning algorithm,high-precision POS data acquisition in dynamic flight is achieved.U-blox's multi-constellation receiver module NEO-M8 T is used to construct the PPK system,combining the BDS/GPS combined positioning algorithm with the LAMBDA ambiguity resolution method,the static positioning accuracy reaches centimeter level,and the dynamic positioning accuracy reaches decimeter level.Finally,a light-weight and low-cost PPK post-differential system was constructed to improve the accuracy of drone flight trajectory recording.(4)Developed an intelligent management system for UAV image data.Combining the needs of UAV data collection and data management,using WEB technology and open source GIS spatial information technology,the overall architecture and functional modules of the UAV image data management system are designed.The data management system is based on the B/S(browser/server)architecture.The front end of the system uses the Vue-cli framework for component-based development,and the Open Layers API is used to load map data.The open source Geo Server server and Postgre SQL database are used as geoprocessing servers and background data respectively.The storage library finally realizes the functions of management and operation of UAV image data,comprehensive information display and interaction,and data sharing.Through image acquisition experiments in two experimental areas,the results show that it is constructed by airborne platform,image and coordinate data synchronization acquisition module,BDS/GPS combined positioning algorithm and LAMBDA ambiguity resolution method,WEB technology and open source GIS spatial information technology The UAV image intelligent acquisition system can meet the technical requirements of the field investigation of land changes.The system can realize the rapid acquisition of the image of land change and the corresponding coordinate information,and upload the data obtained by the drone to the data management system to realize the scientific management of data.