Research on datumn transformation model in particle accelerator component installation

Abstract

When the important components of the particle accelerator are installed, it is required to locate the instrument in the global coordinate system by measuring the control points of the surrounding tunnels, which involves the datumn transformation between the global coordinate system and the station coordinate system, and the selection of the transformation model has gradually become a potential breakthrough in solving the problem. Four different models euler angle, Rodrigues matrix, dual quaternion and twelve parameters are used to analyze and compare the solution parameters, accuracy index, iteration efficiency, and the number of selected common points of the four models with the measured data of 2022 Hefei Light Source summer. The results show that the deviation of the four model parameters from the SpatialAnalyzer commercial software is no more than 3 μm for the translation parameters, and no more than 0.6” for the rotation angle. Among them, the twelve-parameters and dual quaternion two models are theoretically rigorous, with high and stable accuracy indexes, and the twelve parameters posteriori unit weight mean error shows obvious advantages. The twelve parameters and Rodrigues models have fewer iterations and higher efficiency. In summary, the dual quaternion model and twelve parameters method are preferred in the absence of better initial values. In addition, in the process of datumn transformation, along with the increase of the number of common points, the accuracies of all four model solutions show an increasing trend of first fast and then slow.