The invention relates to the technical field of railway measurement, and discloses an unmanned aerial vehicle
LiDAR-based existing
railway line measurement method, which comprises the following steps: S1, ground target
layout: designing square hard white paper targets of which
diagonal lines are black lines, and arranging the targets according to different heights on two sides of a railway in an open area along the railway, adopting a
total station to actually measure the coordinate and elevation of the center of each target; and S2, unmanned aerial vehicle
LiDAR flight: unmanned aerial vehicle
LiDAR equipment adapting to the
measurement precision requirement of the existing
railway line is selected, and flight operation is executed in combination with a ground
base station erection scheme. According to the method, coordinate conversion parameters are established through target arrangement and measured data of a
total station, a
point cloud processing flow is optimized in combination with
intelligent algorithms such as a Ransac
algorithm, 2D
Hough transform and regional growth, the measurement effect that the plane coordinate precision is smaller than or equal to 5 cm and the elevation precision is smaller than or equal to 2 cm is finally achieved, the actual line type of the existing
railway line is precisely restored, and the accuracy of the existing railway line is improved. And the high-precision requirements of maintenance, reconstruction, upgrading and the like are met.