| Orientation of measuring instruments is substantially a process of coordinate transformation.To solve the problem of coordinates transformation in confined space of large-scale measurement,a method of the reciprocal pointing orientation for fast orientation in confined space has been proposed.Focus on two typical large measuring instruments and the measuring princple,orientation can be finished only in case that the instruments are visible to each other in a narrow field of vision by constructing geometric constraint with feature points on instruments themselves.The proposed method is a good supplement of traditional method.The main research work and key technology of this paper are:1.According to the structure of laser tracker,mathematical model and analyze process of the two-face reciprocal pointing orientation are detailed studied.2.An orientation method for workshop Measurement Positioning System(wMPS)based on the reciprocal pointing orientation with feature points is studied.The orientation method of feature points in local coordinate system is described.The establishment of the constraint equation and the solve method of iterative initial value for nonlinear constrained optimization are studied.3.Optimization for the model of the reciprocal pointing orientation is described.In order to choose an appropriate calculation model,various kind of precision influence caused by using different initial values are analyzed and compared.Problem of ill-conditioned matrix is solved by changing model structure.4.Experiments are carried out on the proposed method.The experimental results show that the measurement efficiency is better with the same precision in cofined space.With respect to the orientation method based on the feature points of wMPS,it is more automated and easier to add the measuring unit than traditional method.They can meet the accuracy and efficiency demand of large space measurements in space aviation and big science devices. |
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