Control method for non-linear error between tool nose point and tool axis direction in five-axis machining

Abstract

The invention discloses a control method for the non-linear error between the tool point and the direction of the tool axis in five-axis machining. The command path of the tool axis is obtained from the original machining tool position data, and the ideal path of the tool axis is obtained based on the principle of the shortest path. The deviation between the path and the ideal path is used as the nonlinear error of the tool axis and corrected; the corrected tool position data is converted into processing codes and the command path of the tool tip point in the machine tool coordinate system is obtained, and the tool tip point command path in the machine tool coordinate system is obtained through coordinate transformation. Sharp point theoretical path, find out the point corresponding to the maximum deviation value from the theoretical path in the command path of the tool nose point in the machine tool coordinate system, convert this point to the workpiece coordinate system, and calculate the theoretical path from this point to the tool nose point The straight-line distance is used as the nonlinear error of the tool nose point, and the limit feedrate is obtained from the nonlinear error of the tool nose point, and the target speed is planned with the limit feed rate to compensate the nonlinear error of the tool nose point. The invention improves the machining accuracy and ensures the machining efficiency.

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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