Aimed at tackling the fast solver problem for the large-scale and nearly pathological close-range block sparse bundle adjustment normal equation,the authors propose a solution method based on the preconditioned conjugate gradient(PCG)sparse algorithm. Firstly,the normal equation coefficient matrix corresponding to diagonal matrix square root is selected as the preconditioning matrix by changing the coordinate base of the parameter vector to be estimated, which can improve the behavior of the normal equation coefficient matrix so as to achieve the purpose of improving the convergence rate of the conjugate gradient method. Then, through the application of the sparse matrix, the efficiency of storage can be improved and the adjustment of normal equation coefficient matrix can be achieved. Experiment results show that the method proposed in this paper has the advantage that any scalar change in variables has no effect on the range of convergence of the iterative technique,and hence it has not only high accuracy of calculation but also faster speed.
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2015, Vol. 27 
