五轴联动刀轴矢量平面插补算法

Plane Interpolation of Tool Orientation Algorithm for 5-axis Circumference Milling

大多数数控系统仍默认以旋转轴角度线性插补插补方式进行铣削加工,实际刀轴矢量偏离理论刀轴矢量位置,产生极大的非线性误差。在五轴联动数控加工中心圆周铣削倾斜面时,表现为实际刀轴矢量偏离待加工平面,造成过切或欠切误差。而且,机床类型不同,铣削的误差表现形式也不同。经研究表明,此非线性误差完全来源于旋转轴角度的线性插补方式。从研究分析运动学坐标转换开始,从理论上研究旋转轴角度线性插补的原理和产生非线性加工误差的根源,提出刀轴矢量平面插补具体算法,并针对CA型双摆头类型机床进行仿真验证,新算法从根本上解决了该问题。

The angular linear interpolation method is still applied as the default interpolation method for two rotation axes in the 5-axis milling,which causes an angle of deviation between the actual vector and the theoretical one.The circumference milling brings on an over/under cutting error,whose actual form of machining error lies on the type of machine.After analyzing,it＇s found that the nonlinear error is completely made by angular linear interpolation method.Based on the study of the coordinate transforming method of 5-axis machines,and the angular linear interpolation method of the rotation axis its non-linear error,is the plane interpolation algorithm of tool orientation developed,while the algorithm is reported and tested with the object of a machine with CA-axis swivel head.The result proved that it can resolve the problem of non-linear error.