Method for coordinate error correction with a three-dimensional lidar scanner

A method for coordinate error correction with a three-dimensional (3D) lidar scanner, the 3D lidar scanner comprising a laser ranging module, an azimuth angle measurement module, a pitch angle measurement module and a reflector module;

• the method comprising:
• S1:
• building a theoretical calculation model of a three-dimensional coordinate of a measured point and a azimuth angle, a pitch angle and a distance of the measured point collected by the 3D lidar scanner;
• S2:
• analyzing a source of measurement error comprising errors from installation of the laser ranging module, the azimuth angle measurement module, the pitch angle measurement module and the reflector module of the 3D lidar scanner, and determining an error factor comprising N terms;
• S3:
• building an error model by analyzing a relationship between each of the errors obtained in step S2 and the three-dimensional coordinate of the measured point to generate a calculation expression of a three-dimensional Cartesian coordinate comprising N error factors, the azimuth angle, the pitch angle and the distance;
• S4:
• solving the error model by setting a calibration point group within a full range of the distance, the azimuth angle, and the pitch angle of the three-dimensional scanning lidar, wherein the number of calibration points in the calibration point group is not less than N;
• obtaining a distance, a azimuth angle, and a pitch angle of each of the calibration points through the three-dimensional lidar scanner;
• using a high-precision coordinate measuring instrument to measure each of the calibration points in the calibration point group to obtain a three-dimensional coordinate of each of the calibration points;
• and
• substituting the three-dimensional coordinate of each of the calibration points obtained by the high-precision measuring instrument and the distance, the azimuth angle, and the pitch angle of each of the calibration points measured by the three-dimensional lidar scanner into the error model in step S3 to solve the error factors in the error model and to obtain a corrected three-dimensional coordinate calculation formula;
• and
• S5:
• substituting the distance, the azimuth angle, and the pitch angle of the measured point into the corrected three-dimensional coordinate calculation formula obtained in step S4 to correct the three-dimensional coordinate measured by three-dimensional lidar scanner.