US 12,379,212 B1
Method and device for controlling engineering projection deformation
Zufeng Li, Xi'an (CN); Haowen Yan, Lanzhou (CN); Wenjun Zhao, Xi'an (CN); Shuwen Yang, Lanzhou (CN); Xiaoning Su, Lanzhou (CN); Haixing Shang, Xi'an (CN); Shengjie Di, Xi'an (CN); Zhixuan Miao, Xi'an (CN); Zhao Zhang, Xi'an (CN); and Mingbo Liu, Xi'an (CN)
Assigned to Powerchina Northwest Engineering Corporation Limited, Xi'an (CN); and Lanzhou Jiaotong University, Lanzhou (CN)
Filed by Powerchina Northwest Engineering Corporation Limited, Xi'an (CN); and Lanzhou Jiaotong University, Lanzhou (CN)
Filed on Jan. 24, 2025, as Appl. No. 19/035,827.
Claims priority of application No. 202410933087.1 (CN), filed on Jul. 12, 2024.
Int. Cl. G01C 5/00 (2006.01); G01C 15/02 (2006.01)
CPC G01C 5/00 (2013.01) [G01C 15/02 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for controlling engineering projection deformation, comprising:
calculating, based on known coordinates of an engineering key region, a change rate of a length deformation function per kilometer in a first direction caused by a height difference of the engineering key region and a change rate of the length deformation function per kilometer in the first direction caused by a distance from a central meridian of a Gaussian projection zone of the engineering key region;
solving a distance between a meridian where a center of the engineering key region is located and a new central meridian based on the change rate of the length deformation function per kilometer in the first direction caused by the height difference and the change rate of the length deformation function per kilometer in the first direction caused by the distance from the central meridian of the Gaussian projection zone of the engineering key region;
solving an elevation of a compensation projection plane based on the distance between the meridian where the engineering key region is located and the new central meridian; and
performing comprehensive projection deformation compensation based on the elevation of the compensation projection plane and the distance between the meridian where the center of the engineering key region is located and the new central meridian, so as to realize the controlling of engineering projection deformation;
wherein the calculating, based on known coordinates of an engineering key region, a change rate of a length deformation function per kilometer in a first direction caused by a height difference of the engineering key region comprises:
based on the known coordinates of the engineering key region, calculating an elevation difference between an elevation plane where a side length is located and a reduction projection plane of the side length;
based on the elevation difference between the elevation plane where the side length is located and the reduction projection plane of the side length, calculating a deformation per kilometer of known points of the engineering key region caused by the height difference; and
based on the deformation per kilometer of the known points of the engineering key region caused by the height difference, calculating the change rate of the length deformation function per kilometer in the first direction caused by the height difference of the engineering key region;
wherein the based on the elevation difference between the elevation plane where the side length is located and the reduction projection plane of the side length, calculating a length deformation per kilometer of known points of the engineering key region caused by the height difference comprises:

OG Complex Work Unit Math
where ΔD is the length deformation caused by the height difference; ΔHm is the elevation difference between the elevation plane where the side length is located and the reduction projection plane of the side length; and Rm is an average radius of curvature of the earth.