A Five-Axis NC Interpolation Method Based on Tool Vector Smooth Compression

Abstract

The invention relates to a five-axis numerical control interpolation method based on smooth compression of tool vectors. The five-axis numerical control interpolation method comprises the following steps: judging whether any two adjacent tool vectors meet the conditions of continuous processing according to a read numerical control processing program; if the conditions of continuous processing are met, carrying out compression interpolation of the tool vectors and interpolation of tool nose position; transforming a tool path to transform the tool nose position and tool vector values under a workpiece coordinate system to each axis coordinate under a machine tool coordinate system by utilizing points obtained after compression interpolation of the tool vectors and interpolation of the tool nose position; and fitting two adjacent points after transformation to generate a smooth curve by utilizing a quintic polynomial curve with continuous second derivative. With the adoption of the five-axis numerical control interpolation method, second order continuity of each component of the tool vectors can be ensured, large change of the tool vectors is avoided, nonlinear error generated by dynamic change of a rotation axis in a linear interpolation method is avoided, and the processing precision is improved.

Description

technical field [0001] The invention relates to five-axis numerical control technology in the field of numerical control, in particular to a five-axis numerical control interpolation method based on tool vector smooth compression. Background technique [0002] Compared with three-axis CNC machining, five-axis CNC machining has two degrees of freedom of rotation, which has greater flexibility in interference processing and better machining accuracy, so it is more suitable for high-speed and high-precision machining of complex curved surfaces. [0003] Tool path control is the core function of CNC system. At present, the existing five-axis CNC machining system first performs post-processing on the data in the tool position file, and then implements the linear interpolation method of interpolating the feed axis and changing the direction axis in the machine tool coordinate system. Tool path control, such as figure 1 shown. This tool trajectory control method has the followin...

AI Technical Summary

Problems solved by technology

This tool trajectory control method has the following problems: First, because the change of the tool vector is ignored, it cannot be guaranteed that the tool vector in machining is always on the required plane, resulting in a large difference between the tool nose trajectory in actual machining and the expected trajectory, thus Non-linear errors are generated; secondly, because tool vector interpolation is not considered, large tool vector changes and machine tool angle changes are likely to occur during machining

A large tool vector change will cause a large machining error, and even damage the surface of the workpiece in severe cases; a large angle change will easily lead to the generation of singular points, which will cause a large change in the feed rate during the machining process, resulting in a large impact on the machine tool, and even Make the generated data unusable in actual production

In addition, this tool trajectory control method will generate a large number of NC codes, which will increase the transmission burden of the system and reduce the processing efficiency

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