A b-spline fitting method for five-axis tool path

Abstract

The invention belongs to the numerical control machining related technical field and discloses a B-spline fitting method for a five-axis cutter path. The method includes the following steps that: S1,a five-axis B-spline cutter path is established according to a five-axis discrete cutter path; S2, the maximum chord height difference of the five-axis B-spline cutter path is calculated, and the chord height constraint and smoothness of the five-axis B-spline cutter path are detected, wherein the smoothness of the five-axis B-spline cutter path includes the smoothness of the B-spline path of a cutter location point, and the smoothness and isometric precision of a cutter shaft; and S3, the five-axis B-spline cutter path is adjusted according to the obtained maximum chord height difference of the five-axis B-spline cutter path and the detection result of the smoothness of the five-axis B-spline path of the cutter location point, so that a five-axis B-spline cutter path satisfying a machining requirement is established. With the method of the invention adopted, the quality of the five-axis B-spline cutter path can be comprehensively and efficiently evaluated, and the obtained cutter pathcan satisfy the high-speed and high-precision machining requirement of a five-axis numerically-controlled machine tool.

Description

technical field [0001] The invention belongs to the technical field related to numerical control machining, and more specifically relates to a B-spline fitting method of a five-axis tool trajectory. Background technique [0002] The tool trajectory of five-axis CNC machining is usually represented by a small line segment, and the tool trajectory represented by a small line segment has the following disadvantages: (1) The amount of data storage and transmission is large; (2) The G01 tool trajectory is not continuous at the connection G1 and G2, The speed and acceleration are not smooth during the machining process, thereby reducing the machining accuracy and surface quality of the parts; (3) It does not meet the high-speed and high-precision machining requirements. In actual machining, a parameter curve with better continuity is usually used, such as B-spline curve , fit the tool path represented by the small line segment. [0003] B-spline tool paths should usually satisfy ...

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Problems solved by technology

[0002] The tool trajectory of five-axis CNC machining is usually represented by a small line segment, and the tool trajectory represented by a small line segment has the following disadvantages: (1) The amount of data storage and transmission is large; (2) The G01 tool trajectory is not continuous at the connection G1 and G2, The speed and acceleration are not smooth during the machining process, thereby reducing the machining accuracy and surface quality of the parts; (3) It does not meet the high-speed and high-precision machining requirements. In actual machining, a parameter curve with better continuity is usually used, such as B-spline curve , fitting the tool path represented by a small line segment

[0004] The chord height difference of the B-spline tool path is generally obtained by calculating the Hausdorff distance. B-spline curve fitting of continuous micro-line segment trajectory in machining" all divide the sampling interval equally, and use the Hausdorff distance to calculate the chord height difference between the three-axis B-spline tool and the discrete tool position, but this method does not take into account The chord height difference of the tool axis vector is only applicable to the calculation of the chord height difference of the three-axis B-spline tool path, and the use is limited

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