Method and device for obtaining profile tolerance error of helical surface

Abstract

The invention relates to a method and a device for obtaining a profile tolerance error of a helical surface. The method includes the steps of obtaining a plurality of first three dimensional coordinate values in the first world coordinate system of a plurality of measuring points on a helical surface of a worm through a three coordinate measuring machine; obtaining a plurality of second dimensional coordinate values in the second world coordinate system of a plurality of measuring points through a coordinate transformation of the plurality of the first three dimensional coordinate values; reconstructing a helical surface according to the plurality of the second three dimensional coordinate values and then obtaining an ideal curved surface after the reconstruction; calculating a plurality of minimum distances from the plurality of the first three dimensional coordinate values to the ideal curved surface and searching from the minimum distances, so as to obtain the profile tolerance error of the helical surface. In the invention, a large number of approximate treatments to the three dimensional coordinate values of the measuring points on the helical surface in the prior art are avoided. Therefore, the precision of the profile tolerance error of the helical surface is improved. The method and the device in the invention make the process of solving the profile tolerance error of the helical surface simple and effective, and further improve the precision and efficiency of measuring the helical surface.

Description

Technical field [0001] The invention relates to the technical field of measurement, and in particular to a method and device for obtaining the contour error of a spiral curved surface. Background technique [0002] With the rapid development of the aviation, aerospace, shipbuilding, automobile and mold industries, the application of spiral surfaces has become more and more extensive, and the measurement accuracy and measurement efficiency requirements of spiral surfaces have become higher and higher; because the mathematical model of spiral surfaces is more complex Therefore, there are relatively few studies on the profile error of the spiral surface. [0003] In the prior art, the profile error of the spiral surface is obtained by nonlinear methods (for example: quasi-Newton method, steepest descent method), but due to the high computational complexity of the nonlinear method, the profile error of the spiral surface is increased. Complexity, in order to reduce the complexity of o...

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Problems solved by technology

[0003] In the prior art, the contour error of the helical surface is obtained by nonlinear methods (such as quasi-Newton method, steepest descent method), but due to the high computational complexity of the nonlinear method, the acquisition of the contour error of the helical surface is increased. Complexity, in order to reduce the complexity of contour error acquisition, in the prior art, the contour error of the spiral surface is obtained by using the least square method. Since the least square method is a linear method, it greatly simplifies the process of obtaining the contour error of the spiral surface. process, thereby improving the efficiency of obtaining the contour error; however, the least square method approximates the coordinate values ​​of the measurement points on the spiral surface in the process of obtaining the contour error of the helical surface, thus reducing the error of the contour precision

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