The optimal arrangement of four laser tracking interferometers in 3D coordinate measuring system based on multi-lateration

The measuring accuracy of four-beam laser tracking system for 3D coordinate measurement in large degree depends on the arrangement of the interferometers. In this paper the optimal arrangement of four laser tracking interferometers is proposed. The optimal arrangement for measurement is obtained through minimizing the position dilution of position (PDOP) of the measured point. Not only the process of measurement but also the process of self-calibration are influenced by the system arrangement. The relationship between the accuracy of self-calibration and system arrangement is also discussed through computer simulations and experiments. The results show that the nominal arrangement defined in this paper can be considered as the optimal arrangement for 3D coordinate measuring systems based on multi-lateration.