拟 合 精 度 约 束 下 航 发 叶 片 在 机 测 量 采 样 策 略

The number of measurement points is a key factor impacting the on-machine measurement efficiency of complex surfaces on aero-engine blades. To minimize the number of measurement points while meeting the fitting ac⁃ curacy requirements，a sampling approach for blade on-machine measurement that considers the fitting accuracy is proposed. Firstly，in terms of the evaluation characteristics of surfaces inspection on blade body，the evaluation of fit⁃ ting accuracy of surfaces is simplified to the evaluation of fitting accuracy for a set of section profile curves，and a model to assess the error relationship between different fitting curves is established. Then，the fitting error is separated from the on-machine measurement results by using the scaling transformation，and the upper bound model of fitting er⁃ ror is established. Furthermore，with the constraint that the upper bound of the fitting error satisfies the given fitting tol⁃ erance，the minimum number of measurement points is calculated iteratively based on the approximation error prin⁃ ciple. Finally，taking the centrifugal impeller as the verification object，the number of measurement points can be re⁃ duced，and the measurement efficiency can be improved by the proposed method while ensuring the fitting accuracy of the on-machine measurement results，which provides a new approach to optimize the on-machine measurement process for the curved surface parts.