Calibration of theodolites

Concepts leading to an accurate, automated system for making 3D measurements of robot position are described. The system is predicated on building complete kinematic models of the measurement apparatus and determining the model parameters from data obtained in a calibration procedure. The two primary calibration procedures required are the determination of the geometric parameters of the individual theodolites and the determination of the triangulation baseline, the six-degree-of-freedom relationship between two theodolites. The former are described. Simulations and an experiment testing the theodolite calibration procedures are reported. The results suggest that the methods described, when used in conjunction with high quality commercially available theodolites (measurement errors <2 arcseconds), allow the construction of an automated triangulation system with measurement accuracy approaching 1:10⁵