Fly Route Optimization And Experimental Analysis In Aerial Survey Accuracy Of Multi-Rotor UAV

The aerial photogrammetry technology of the professional photogrammetry aircraft and aerophotographical camera have already been highly mature, given the fact that its methods of data producting and measurement precision have been fully verified both in theoretical research and production practices. The multi-rotor unmanned aerial vehicles with non-metric camera, as a new type of photogrammetry, overweighs the manned aircraft and the fixed-wing unmanned aerial vehicles in terms of low cost, flexibility and high accuracy, and thus becomes a new frontier in the area of aerial photography. Therefore, it is of vital importance to study and solve the relevant technical problems with full consideration of the characteristics of the new aerial photography surveying system.The main research contents of this paper are as follows:(1) Study on the basic components and characters of the multi-rotor unmanned aerial vehicles’ photogrammetric system. Generally, the multi-rotor unmanned aerial vehicles’ photogrammetric system consists of flying platform, flight control system, remote-control system, attitude stabilization and control system(aerial gimbals), photographic apparatus, data transmission system as well as ground station system. This system is possessed of qualities such as low cost, flexibility and high quality of photograph. However limited by the power mode and load capacity of flying platform, the multi-rotor unmanned aerial vehicles photogrammetric system is confined to mount light non-metric camera for now, and its cruising duration is short. Meanwhile, the acquired data are characterized with low base-height ratio, low phase and amplitude and high level of overlap.(2) Study on the optimization algorithm of route planning with respect to the water surface feature. Given the fact that some photogrammetry areas contain a large number of water areas(such as large reservoirs), it will lead to numberous waste images of the water surface if following the continuous regular route. Taking the cruising capacity of the multi-rotor unmanned aerial vehicles into account, this paper presents a optimization algorithm of route planning considering the water surface feature, by decomposition of the air strips and iterative computation of its length to reduce waste, to improve the efficiency of single sortie and reduce the total flying sorties. Finally, this paper develops the route planning optimization system in combination with the multi-rotor unmanned ground station and performs the experimental tests.(3) Study on the measurement accuracy of the multi-rotor unmanned aerial vehicles photogrammetric system. For the data of high ground resolution and different degrees of overlap, this paper uses the camera calibration, field surveying of image control point and internal data processing to compare and analyze the plane accuracy and elevation precision, aiming to provide the scientific basis for the production and research of the multi-rotor unmanned aerial vehicles’ photogrammetric system.