The data alignment and comparison of three dimensional measurement for hull blocks

In order to get geometric deviation of ship hull blocks, the alignment between measuring data and model data is the prerequisites to achieve the data analysis. Brayden-Fletcher Goldfarb-Shanno(BFGS) algorithm was proposed with initial alignment. The algorithm takes use of initial alignment in order to minimize deviation between the transformed hull block measured data and model data. Object function is established based on least square principle and the global optimal parameters are derived by the unconstrained optimization algorithm based on BFGS algorithm. By means of analysis after alignment, the results could predict the geometric deviation of hull blocks accurately and provide an instructive basis for subsequent block modification and assembly.