Control method for nonlinear error between five-axis machining tool nose point and tool axis direction

Abstract

The invention discloses a control method for a nonlinear error between a five-axis machining tool nose point and a tool axis direction, and the method comprises the steps: obtaining a tool axis instruction path through original machining tool position data, obtaining a tool axis ideal path based on a shortest path principle, taking the deviation between the tool axis instruction path and the idealpath as a tool axis nonlinear error, and correcting the tool axis nonlinear error; converting the corrected tool position data into a machining code, obtaining a tool nose point instruction path under a machine tool coordinate system, obtaining a tool nose point theoretical path under the machine tool coordinate system through coordinate conversion, and finding out a point corresponding to the maximum deviation value with the theoretical path in the tool nose point instruction path under the machine tool coordinate system; converting the point into a workpiece coordinate system, calculating the linear distance from the point to the theoretical path of the tool nose point to serve as the nonlinear error of the tool nose point, solving the limit feed rate according to the nonlinear error ofthe tool nose point, planning the target speed according to the limit feed rate, and compensating the nonlinear error of the tool nose point. According to the invention, the machining efficiency is ensured while the machining precision is improved.

Description

technical field [0001] The invention relates to the technical field of numerical control in mechanical manufacturing engineering technology, in particular to a control method aiming at the non-linear error between a tool tip point and a tool axis direction in five-axis machining. Background technique [0002] The five-axis machine tool plays an important role in the processing of complex curved surface parts. Due to the addition of two rotating axes, the position and attitude of the tool change at the same time, realizing the processing method that the three-axis machine tool cannot complete, saving processing time and improving the efficiency. Precision. When the CAM software generates the tool position file of the five-axis machine tool, the representation form of the tool attitude is a vector. The gradual change of the theoretical tool attitude assumes that the workpiece is stationary and the tool tip is the fixed point, while the change of the tool attitude in actual mac...

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Problems solved by technology

The document "HONG Xinyu, HONG Rongjing, LINXiaochuan. Tool orientations' generation and nonlinear error control based on complex surface meshing [J]. The International Journal of Advanced Manufacturing Technology, 2019, 105(10): 4279-4288." For linear error, the method of linear interpolation of angular coordinates is used to ensure the smooth acceleration of the rotation axis. In the part where the error exceeds, the method of inserting the midpoint vector is adopted. However, due to the nonlinear correspondence between the error and the point distance, this method will cause a decrease in processing efficiency. loss

While considering the tool axis direction and the nonlinear error of the tool tip point at the same time, such as the literature "HAN Jiang, LIU Xiuyu, JIANG Yang, et al.An irreredundant G01 tool path generation method for five-axis machining considering tool tip and orientation errors[J] .The International Journal of Advanced Manufacturing Technology, 2019, 103(1-4): 1033-1044." For the double turntable structure, the iterative algorithm is used to generate non-redundant tool point, but this method ignores the speed planning and interpolation link, which will further reduce the tool point error

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