Dynamic calibration and compensation method of a large-scale laser beam based on specular reflection for a nonorthogonal shaft laser theodolite measurement system.

Abstract

The nonorthogonal shaft laser theodolite (N-theodolite) measurement system is a new kind of instrument that can be applied to large-scale metrology. Different from traditional theodolites, the three axes of the N-theodolite have no requirements on the orthogonality and intersection. For the measurement in laser scale, the parameters of the system on a large scale must be known. A calibration method of the laser beam based on specular reflection and its compensation are proposed, which are at a range of 12 m. Through the experiments, the results show that the straightness accuracy of the laser beam of the left N-theodolite is 0.12 mm at a range of 12 m, and the right one is 0.14 mm. Through the measurement experiments, the maximum measurement deviation of the system is 0.27 mm, which is verified to be a feasible method to calibrate the laser beam in large-scale space.