五坐标数控加工的非线性运动误差分析与控制

分析了五坐标联动数控系统采用线性五轴插补运动时,与实际的空间非线性连续轨迹之间的理论加工误差;用空间解析几何、齐次坐标变换建立了双转台结构五坐标机床的运动变换数学模型,并结合五坐标数控机床加工过程的线性插补原理,建立了该类五坐标机床的非线性运动误差估计模型,提出了一种非线性误差控制策略.通过仿真分析和试验加工对该模型和控制策略进行了验证.

Analysis and Control of the Non-linear Errors in Five-axis NC Machining

This article analyzed the theoretical errors resulted from approximating the perfect continuous tool path with linear interpolation in 5-axis machining,and this kind of error is also called non-linear motion errors or known as the geometry-based errors.A kinematics transformation of 5-axis milling machine of table-table type was established based on the analytic geometry and transformation matrix.An expression used to estimate the non-linear motion errors was given on the base of linear interpolation principle widely used in 5-axis CNC software and a strategy for controlling non-linear motion errors was also presented which is verified by simulation and machining tests that the machining errors can be controlled effectively.