Unmanned aerial vehicle tree diameter measuring method based on optical flow method

Abstract

The invention discloses an unmanned aerial vehicle tree diameter measuring method based on an optical flow method. A tree board, an unmanned aerial vehicle and data processing equipment are used as measuring devices to measure and calculate the tree diameter, and the tree board is used for marking the number of a tree and the measuring position of the diameter at breast height; the unmanned aerial vehicle is provided with a monocular lens and an ultrasonic sensor, the monocular lens is used for shooting tree boards and tree trunks, and the ultrasonic sensor is used for keeping the unmanned aerial vehicle and the tree boards at corresponding heights; the data processing equipment is used for planning the route of the unmanned aerial vehicle, detecting tree boards in videos shot by the unmanned aerial vehicle, identifying numbers of the tree boards, and measuring the diameter at breast height of a tree trunk where the tree boards are located based on an optical flow method to complete tree diameter measurement. According to the method, the tree diameter can be measured quickly and accurately in batches in a high-automation mode, the method is easy to operate, manpower and time are greatly saved, the efficiency and accuracy of large-scale tree diameter measurement are improved, a complete tree diameter database is established, management and calling are convenient, and according to the tree diameter measuring and calculating method based on the optical flow method, the calculation precision is guaranteed while only a small number of calculation resources are needed.

Description

technical field [0001] The invention belongs to the field of intelligent measurement, and relates to the application of unmanned aerial vehicles in the field of tree diameter measurement, in particular to a method for measuring tree diameters of unmanned aerial vehicles based on an optical flow method. Background technique [0002] In the fields of garden planting, forest investigation and ecological forestry, it is necessary to measure trees regularly to achieve accurate inventory of tree resources, quality and growth. The size of the tree diameter is an important indicator to study the condition of trees, and it is an extremely important investigation content. [0003] The methods of tree diameter measurement mainly include manual measurement, hand-held measuring instrument and drone measurement. Manual measurement: mainly rely on manual estimation, use tape measure or caliper to measure tree diameter. The disadvantage of this method is that it is inefficient and require...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that it is inefficient and requires a lot of manpower and time

Hand-held measuring instrument: Although the tree diameter can be measured in a non-contact manner, it is still necessary for the surveyor to personally measure each tree, which is labor-intensive and time-consuming

At the same time, surveyors need to learn how to operate the handheld measuring instrument, which increases the learning cost

In addition, since surveyors work in the field, there are also high requirements for the portability of handheld devices.

UAV measurement: The existing methods require the UAV to be equipped with IMU inertial measurement units, microcontrollers, and laser radars, and require manual remote control of the UAV to scan the point cloud data for multiple flights and identify the discrete points of the tree trunk. The main disadvantage of this method is that the equipment is complicated, the operation is cumbersome, and the calculation method is complicated, which consumes a lot of computing resources and cannot guarantee the calculation accuracy.

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