六轴五联动数控加工非线性误差的分析与控制

Analysis and Control of Nonlinear Error in Six-Axis Five-Linkage CNC Machining

多轴联动数控加工中数控系统线性插补和实际刀具轨迹的不一致性,导致了非线性误差的产生。通过建立非线性误差模型,预测了最大非线性误差的位置;通过分析曲线拟合度并采用抛物线函数法进一步完善误差模型,分析非线性误差的影响因素;通过自适应线性化法将超差程序段控制在误差允值范围内。以圆盘刀六轴五联动数控加工叶片曲面为例,对其刀位文件进行仿真分析,控制后采样程序段的非线性误差得到明显改善,最大非线性误差的标准差降低近84.5%,验证了该控制方法的有效性。

Due to the inconsistency between the linear interpolation of CNC system and the actual tool path in multiaxis CNC machining,the nonlinear error is caused.In this study,the nonlinear error model is established to predict the position of the maximum nonlinear error,the parabola function method is used to further optimization the error model by analyzing the curve fitting degree,and the influence factors of nonlinear error are analyzed.The overerror program segment is controlled within the allowable value of error by adaptive linearization method.Taking the six-axis and five-linkage CNC machining of blade surface with disk knife as an example,the tool position file is simulated and analyzed.The nonlinear error of sampling program section is obviously improved after control,and the standard deviation of maximum nonlinear error is reduced by nearly 84.5%.The effectiveness of the above control method is verified.