5轴加工奇异区域非线性误差控制方法

Non-linear Error Control Method for Five-axis Machining Singular Zone

5轴数控机床在加工奇异区域时,由于旋转轴的剧烈变化导致产生较大的非线性误差,加工质量下降。针对这个问题,以A-C双转台机床为例,分析机床产生奇异现象的原因,提出检测5轴加工奇异区域的方案,通过对奇异区域相邻刀轴矢量之间进行插值处理,减小相邻刀轴的角度变化,使相邻刀位点之间的最大非线性误差小于机床允许的最大非线性误差。用MATLAB对比插值前后5轴机床转角和非线性误差的变化,证明该方法可以降低C轴的过大转角同时减小非线性误差。

When a five-axis NC machine tool is working in singular areas,the drastic change of the rotating axis results in a large non-linear error,and the processing quality decreases.Aiming at this problem,taking A-C double turntable machine tool as an example,this paper analyses the causes of singular phenomenon of machine tool,and puts forward a scheme of detecting singular area of five-axis machining.By interpolating the vectors of adjacent tool axes in singular area,the angle variation of adjacent tool axes is reduced,and the maximum non-linear error between adjacent tool locations is less than the maximum allowable non-linear error of machine tool.By comparing the change of rotation angle and non-linear error of five-axis machine tool before and after interpolation with MATLAB,it is proved that this method can reduce the excessive rotation angle of C-axis and the non-linear error at the same time.