面向一种新型并联动力头的点矢混合插补方法

Point-vector-blending Interpolation Method of a Novel Parallel Spindle

为满足一种新型三坐标并联动力头物理样机数控系统的开发需求,研究了五轴数控加工中的点矢混合插补方法,提出了一种基于Hermite插值的双曲线插补算法。分析了并联动力头的姿态变换和关节驱动参数的求解,由数控代码信息建立末端参考点和辅助参考点的位置点集,并运用线性插值方法估计各点上的导矢方向,根据进给速率运用Hermite插值方法在各坐标轴进行插补计算。仿真实验证明了Hermite双曲线插补方法在同等条件下可获得较线性插补和平面矢量插补更好的位姿插补精度,适合于高速高精度自由曲线曲面运动控制。

A point-vector-blending interpolation method in five-axis machining is studied for meeting the requirement of the CNC development and afterward machining experiments. A double curve interpolation method based on Hermite polynomial interpolation algorithm is proposed in this paper. Though the kinematics analysis,the posture transformation and joint drive parameters of the parallel power head are discussed for interpolation. Point sets are established according to the information provided by NC codes,the linear interpolation is utilized to estimate the vector direction on every point,and the coarse interpolation is accomplished by using the Hermite algorithm. The simulations are implemented by considering the motion pattern,and results prove that the double curve interpolation algorithm can achieve better position and pose precision. Compared with the linear interpolation and the plane vector interpolation method,the double curve interpolation method satisfies the demand of the development of CNC and machining experiments.