五轴联动刀轴矢量插补优化算法

目的研究解决五轴联动机床旋转轴角度采用线性插补方式生成的加工轨迹,导致刀具姿态偏离所设计的理想平面,引发刀具姿态误差的问题,减少非线性误差,提高零件表面质量。方法首先对旋转轴角度线性插补方式引发刀具姿态误差的原理进行了分析,提出了一种刀轴矢量插补优化算法。然后在线性插补的基础上,根据提出的刀轴矢量插补优化算法保证首末点间的刀轴插补矢量始终位于首末刀轴矢量所构成的平面内,实现刀具姿态优化,并在MATLAB中对线性插补和矢量插补优化两种方式进行仿真分析,观测出对应方式下刀轴插补矢量的空间位置。最后利用叶片试件在AB型转台摆头类型机床上进行仿真和加工验证,对比两种刀轴矢量插补方式仿真数据。结果在VERICUT同等条件下仿真,刀轴矢量采用线性插补时,叶片进出汽边误差值分别为-0.218 66 mm和-0.312 58 mm;刀轴矢量插补优化后,叶片进出汽边误差值分别为-0.095 46 mm和-0.099 05 mm。刀具姿态经过插补优化算法后,叶片进出汽边的过切值明显降低。结论刀具姿态经过插补优化算法后,叶片过切值的大小和数目明显减少,使得非线性误差明显降低,从而提高了零件表面质量。

Optimization Algorithm of Tool Axis Vector Interpolation in Five-axis Linkage

The work aims to solve the problem of tool attitude deviation from designed ideal plane due to machining trajectory of rotary axis angle of the five-axis linkage machine in linearinterpolation mode, reduce nonlinear error and improve surface quality of parts. Principle of tool attitude error caused by linear interpolation mode of rotary axis was analyzed, and an optimization algorithm of tool axis vector interpolation was proposed. Then, based on the proposed algorithm, the tool axis vector interpolation algorithm wasadopted to ensure that the tool axis interpolation vector between the first and last points was always in the plane formed by the first and last tool axis vectors,and the tool attitude optimization was realized. The two modeswere simulated and analyzed in MATLAB, and spatial position of the tool axis interpolation vector in corresponding mode was observed. Finally, simulation and machining verification were carried out on AB turntable pendulum type machine by using blade specimen, and simulation data of the two tool axis vectorinterpolation modes was compared. During simulation under the same VERICUT conditions, error value on the side of blade inlet and outlet was -0.218 66 mm and -0.312 58 mm, respectively when linear interpolation was applied to the tool axis vector, error values on the side of inlet and outlet was -0.095 46 mm and -0.099 05 mm, respectively after error blade cutter axis vector interpolation was optimized. After the tool attitudewas optimizedby interpolation algorithm, overcut value on the side of blade inlet and outlet was obviously reduced. As soon as tool attitude is optimized by interpolation algorithm, both size and number of overcut value of the blade decrease obviously, which significantly reduces nonlinear error and thus improves surface quality of parts.