Method for determining optimal measuring point number of free-form surface detection

Abstract

The invention aims to provide a free-form surface detection optimal measurement point number determination method, which comprises the following steps of: setting four groups of test schemes, and carrying out surface detection to obtain four groups of shape errors; if the four groups of shape errors are all smaller than the shape tolerance, adding a group of schemes with more measuring points as a fifth group of testing schemes; constructing a gray prediction GM (1, 1) model, and predicting to obtain a fifth group of prediction shape errors; based on the gray interval range, judging whether the processing technology has problems or not; according to the fifth group of test schemes, performing curved surface detection by adopting a high-precision three-coordinate measuring machine to obtain a fifth group of shape errors; comparing whether the absolute value of the difference between the last two groups of detected shape errors is smaller than a threshold value or not, and if so, obtaining an optimal free-form surface measuring point number; otherwise, deleting the first group, changing the second to fifth groups into new first to fourth groups, then adding a scheme of more measuring points as a new fifth group, and repeating the steps. The detection efficiency can be improved.

Description

technical field [0001] The invention relates to the field of part measurement, in particular to a method for determining the optimal number of measuring points for free-form surface detection. Background technique [0002] With the rapid development of modern technology, the application of free-form surfaces has become more and more extensive, and at the same time, modern manufacturing has put forward higher precision testing requirements for them. Surface measurement accuracy is affected by many factors, such as detection environment, detection method, sampling parameters and so on. When obtaining the machining error of free-form surfaces, due to the characteristics of free-form surfaces, it is often necessary to determine the optimal number of measuring points. Existing methods usually use free-form surface error model analysis and use a large number of data comparisons to determine the optimal number of measuring points. In the process of traditional testing, in order to...

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Problems solved by technology

In the process of traditional testing, in order to determine a better number of measuring points, a large amount of historical

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