Research On Uncertainty Of Coordinate Measurement For Large Scale Geometry

Coordinate measurement techniques are widely used in the large-scale geometrical measurement at present, however, there are still some problems about the coordinate measurement technique, such as the evaluation of measurement uncertainty and the task-specific measurement planning. To meet the requirements of the large-scale measurement and uncertainty estimating, this paper investigates sources of uncertainty, the expression of measurement project and the uncertainty evaluation techniques based on simulation, the contents and achievements are as follows:(1)Based on the research of the basic process of coordinate measurement and the factors that contribute to the uncertainties, the overall framework is established to address the uncertainty evaluation and measurement method programming based on numerical simulation.(2)The requirements of Geometrical Product Specification and verification(GPS) are analyzed, basic algorithms library for measurement is developed, the uncertainty of basic GPS operators is evaluated, and the evaluation approach is validated via examples.(3) By introducing the conception and method of labeled ordered tree, flow model of measurement based on ordered tree is deeply researched. This model not only makes clear of measurement steps, but also includes the GPS operators in detail, it is the foundation for the automatic processing of the measuring data.(4)In allusion to the actual problems of missile measurement, on the basis of the achievements of this paper, the measuring approach based on ordered tree is proposed. Simulation data are generated corresponding to the metrological data and the measurement project is analyzed by computer simulation, which validates the feasibility and correctness of the main approach.