Free-form surface adaptive machining track planning method

Abstract

The invention discloses a free-form surface adaptive machining track planning method which is mainly used to grind free-form surface parts. The method comprises the following steps: getting the main curvature extremum of a surface through a genetic algorithm; getting the maximum line spacing suitable for surface machining according to the precision need; discretizing the longest boundary of the surface at equal step length through dichotomy; acquiring the related parameters of discrete points and calculating adjacent track cutter contacts; after traversing all newly-generated cutter contacts, performing interpolation according to the step length requirement and smoothing; and until the discrete points cover the whole surface, fitting the cutter contacts to generate a machining track. According to the invention, the maximum machining line spacing is obtained according to the machining precision requirement and the surface characteristics, and by achieving a best fitting effect between a grinding head and a surface and self-adaption of the line spacing direction, over-cutting and vibration caused by repeated grinding of a local area are avoided, and the grinding efficiency and grinding accuracy are improved. The method has great popularization and practical values.

Description

technical field [0001] The invention belongs to the technical field of numerical control machining, and specifically relates to an adaptive grinding trajectory planning method in the process of high-speed and high-precision machining of free-form surfaces. technical background [0002] Freeform surface parts are widely used in aerospace, shipbuilding, automobiles, mold manufacturing and other fields due to their excellent aerodynamics, fluid dynamics and thermodynamics. With the development of multi-axis linkage machining, the NC machining programming of free-form surface, as one of the key technologies to realize free-form surface machining, has become more and more important. In particular, the research on its tool path trajectory planning technology has become a research in this field. Hotspots and Difficulties. [0003] Freeform surface tool trajectory planning is a core development direction of CNC technology, and its planned trajectory quality has a direct impact on t...

AI Technical Summary

Problems solved by technology

However, in the isoparameter method, two adjacent isoparameter line tool paths with fixed parameter intervals are not equidistant in space, so in order to meet the processing requirements, the trajectory has to be encrypted in actual processing, which seriously affects its processing efficiency and accuracy; The cross-section line method is too complicated to calculate the intersection line of two surfaces continuously, and the calculation efficiency is low; the calculation of the equidistant surface of the projection method itself is a complicated problem and it is difficult to obtain an accurate offset surface

However, in the trajectory planning of wide-row processing of free-form surfaces, there is a problem of the minimum overlap between adjacent trajectories.

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