US 12,353,507 B1
Method for determining error component of photoelectric theodolite and method for compensating error component of photoelectric theodolite
Shixue Zhang, Changchun (CN); Jinyu Zhao, Changchun (CN); Jialiang Liu, Changchun (CN); Haojing Wang, Changchun (CN); Peifeng Wei, Changchun (CN); and Junchi Liu, Changchun (CN)
Assigned to Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun (CN)
Filed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun (CN)
Filed on Apr. 16, 2025, as Appl. No. 19/181,277.
Claims priority of application No. 202411606426.1 (CN), filed on Nov. 12, 2024.
Int. Cl. G06F 17/18 (2006.01); G01C 1/02 (2006.01); G01C 25/00 (2006.01); G06F 17/11 (2006.01)
CPC G06F 17/18 (2013.01) [G01C 1/02 (2013.01); G01C 25/00 (2013.01); G06F 17/11 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for determining an error component of a photoelectric theodolite, comprising:
S1: dividing a celestial region uniformly into a plurality of sub-regions, and selecting a star in each sub-region as a reference star of the sub-region;
S2: calculating guidance data for guiding the photoelectric theodolite according to a theoretical position of the reference star;
S3: guiding the photoelectric theodolite to point at the reference star according to the guidance data, and recording an encoder value and a target deviation value of the photoelectric theodolite;
S4: fitting the encoder value and the target deviation value into an actual pointing of the photoelectric theodolite, and calculating an azimuth deviation ΔA and an elevation deviation ΔE of the photoelectric theodolite according to the actual pointing and the guidance data, wherein the azimuth deviation ΔA represents a difference between an azimuth angle of the actual pointing and an azimuth angle of the guidance data, and the elevation deviation ΔE represents a difference between an elevation angle of the actual pointing and an elevation angle of the guidance data;
S5: establishing an axis systematic error pointing model for the photoelectric theodolite according to the azimuth deviation ΔA and the elevation deviation ΔE, wherein the axis systematic error pointing model is expressed as:

OG Complex Work Unit Math
S6: establishing an azimuth error equation and an elevation error equation for the photoelectric theodolite according to the axis systematic error pointing model for the photoelectric theodolite, wherein the azimuth error equation and the elevation error equation for the photoelectric theodolite are respectively expressed as:

OG Complex Work Unit Math

OG Complex Work Unit Math
where v1 represents a horizontal component of a vertical axis tilt error of the photoelectric theodolite, v2 represents a vertical component of the vertical axis tilt error of the photoelectric theodolite, AM represents a measured azimuth angle of a corresponding reference star, EM represents a measured elevation angle of the corresponding reference star, n represents the number of reference stars, g represents an orientation error of the photoelectric theodolite, c represents a collimation error of the photoelectric theodolite, b represents a horizontal axis tilt error of the photoelectric theodolite, r represents a coefficient of an elevation error caused by gravity sag, h represents a zero-point error of the photoelectric theodolite, and g, c, b, r and h are error components of the photoelectric theodolite;
S7: calculating a least squares estimated value of an azimuth error component and a least squares estimated value of an elevation error component according to the azimuth error equation and the elevation error equation of the photoelectric theodolite; and
S8: calculating a pointing fitting residual for each reference star according to the least squares estimated value of the azimuth error component and the least squares estimated value of the elevation error component, calculating a standard deviation according to the pointing fitting residuals, and sequentially determining whether each pointing fitting residual is greater than three times the standard deviation; if the pointing fitting residual of a reference start is greater than three times the standard deviation, excluding the reference star and re-executing S1 to S8 based on the remaining reference stars until the pointing fitting residual of each remaining reference star is not greater than three times the standard deviation, so as to obtain a final least squares estimated value of the azimuth error component and a final least squares estimated value of the elevation error component.