Control and optimization of UAV measurement parameters for alignment measurement in bridge construction

Alignment measurement is necessary during the process of bridge construction. However, traditional measurement methods consume a lot of time and labor, especially for long-distance measurement. UAV photogrammetry has the advantages of high manoeuvrability, low cost, and independence on labour. The application of UAV to bridge alignment measurement can improve efficiency and promote construction control automation. In this paper, the framework and control parameters of UAV photogrammetry was studied. Experimental study was conducted to investigate the effect of parameters on the measurement accuracy including flying height, angle of bundle, camera position and photo quantity. On this basis, the optimal parameters for bridge alignment photogrammetry are summarized. With the optimized measurement scheme, the coordinate measurement accuracy of each point can reach millimetre level.