基于G代码的五轴数控机床轮廓误差计算

Calculation of Contour Error in Five-Axis CNC Machine Based on G-Code

摘要: 动态误差是影响五轴数控机床加工精度的重要因素，尤其在高速、高精度加工时最为明显。进行动态误差的补偿研究需要建立一个精准的模型，现有的轮廓误差计算模型难以适用于不同类型机床。针对以上缺点，文章提出了基于G代码的五轴数控机床动态误差建模研究，以S型试件G代码为例，首先进行数控机床数据采集，采集理想位置和实际位置，将G代码按照采集理想位置进行抽样使两者数量一样。G代码抽样值与采集的实际位置、采集的理想位置和采集的实际位置分别进行轮廓误差的计算，作为仿真与实际进行对比。结果显示提出的基于G代码抽样的轮廓误差计算方法有很好的精度，仿真与实际误差值很接近，刀尖误差都在0.02 mm以内，刀轴误差都在0.001 rad以内。这表明了文章提出的轮廓误差估计方法的有效性，为后续基于G代码的五轴数控机床动态误差的控制提供了参考价值。

Abstract: Dynamic error is an important factor affecting the machining accuracy of five-axis CNC machine tools, especially in high-speed and high-precision machining. An accurate model shall be established for dynamic error compensation research, and the existing contour error calculation model is difficult to apply to different types of machine tools. Aiming at the above shortcomings, this paper puts forward the research on dynamic error modeling of a five-axis CNC machine tool based on G code. Taking the G code of the S-type test piece as an example, firstly, the data of the CNC machine tool is collected, the ideal position and the actual position are collected, and the G code is sampled according to the ideal position to make the two numbers the same. The G code sampling value and the actual position acquired, the ideal position acquired, and the actual position acquired are respectively calculated for contour error, which is compared with the actual simulation. The results show that the contour error calculation method based on G code sampling has good accuracy, the simulation error value is very close to the actual error value, the tool point error is within 0.02 mm, the tool axis error is within 0.001 rad, the results verify the effectiveness of the contour error estimation method proposed in this paper, and provide reference value for the follow-up control of dynamic error of five-axis CNC machine tool based on G code.