The application discloses a
power transmission line sag identification and early warning method and device combined with
zoom ranging, relates to the technical field of
power transmission line monitoring, and comprises the following steps: installing a binocular camera
system in a target identification scene, adjusting variable focus lens parameters, calibrating the binocular camera
system by using a
checkerboard, and constructing a disparity-
depth mapping relationship; collecting Q times of synchronous images by using the calibrated
system, performing multi-point disparity analysis, obtaining disparity analysis results of a first suspension point, a second suspension point and a sag lowest point, and screening and determining target suspension point and sag lowest point analysis results; taking the results as indexes, searching the disparity-
depth mapping relationship, and obtaining depth information; calculating target suspension point
ranging results according to the depth information, calculating a sag value and judging whether the sag value exceeds a threshold value, and if not, triggering early warning, so as to solve the technical problem that a traditional
ranging mode cannot feed back sag changes in real time, and thus cannot effectively early warn safety hazards caused by excessively large sag.