US 12,339,240 B2
Method for detection of soil heavy metal pollution using unmanned aerial vehicle (UAV) and X-ray fluorescence (XRF) technology
Fang Huang, Chengdu (CN); Shuying Peng, Chengdu (CN); Hao Yang, Chengdu (CN); and Shengyi Chen, Chengdu (CN)
Assigned to UNIVERSITY OF ELECTRONIC SCIENCE AND TECHNOLOGY OF CHINA, Chengdu (CN)
Filed by UNIVERSITY OF ELECTRONIC SCIENCE AND TECHNOLOGY OF CHINA, Chengdu (CN)
Filed on Apr. 13, 2022, as Appl. No. 17/719,859.
Claims priority of application No. 202110498045.6 (CN), filed on May 8, 2021.
Prior Publication US 2022/0365007 A1, Nov. 17, 2022
Int. Cl. G01N 23/223 (2006.01); B64U 101/00 (2023.01); G01C 21/20 (2006.01); G01N 33/24 (2006.01); G01S 19/45 (2010.01); G05D 1/00 (2024.01)
CPC G01N 23/223 (2013.01) [G01C 21/20 (2013.01); G01N 33/24 (2013.01); G01S 19/45 (2013.01); G05D 1/101 (2013.01); B64U 2101/00 (2023.01); G01N 2223/076 (2013.01); G01N 2223/507 (2013.01); G01N 2223/616 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for detection of soil heavy metal pollution using an unmanned aerial vehicle (UAV) and an X-ray fluorescence (XRF) technology, comprising the following steps:
Step 1, uniformly selecting enough sampling points in an area to be detected using an XRF analyzer, and detecting each sampling point respectively near ground and on the ground to obtain content data of a set of metal elements to be detected;
Step 2, performing data check and data preprocessing, wherein after data acquisition is completed, a scatter plot is drawn from known data for data check, wrong data is eliminated, and a fitting degree n of a polynomial (or similar model) is determined according to preliminary data;
Step 3, calculating polynomial fitting functions with highest degrees of n−1 and n and a sum of squared errors successively;
Step 4, if a reduction amount of the sum of squared errors of a last fitting function compared with the sum of squared errors of a previous fitting function is greater than a set threshold, continuing to calculate the fitting function with a highest order greater than n successively until a reduction amount of a final sum of squared errors compared with the sum of squared errors of the previous fitting function is less than a set threshold;
Step 5, recording and saving a fitting function corresponding to a minimum sum of squared errors as a final inversion model; and
Step 6, controlling the UAV to hover at an altitude of h2 accurately acquiring, by the XRF analyzer carried or the UAV, soil data near the ground, and detecting, by the XRF analyzer accurate content data of heavy metal elements in soil by performing inversion on the soil data based on the final inversion model, wherein h2 is the altitude for acquiring the soul data near the ground.