基于轴向自适应的曲线插补算法

Axial self-adaptability based curve interpolation algorithm

高速加工中各运动轴上的动力学状态将直接影响机床运行的平稳性和工件尺寸精度,而传统的自由曲线插补算法没有很好地考虑插补运动在各轴上的影响.为此提出一种新的非均匀有理B样条(NURBS)曲线插补算法(ALANI).该算法在保证插补轮廓精度的基础上,将各轴上的加速度分量严格控制在相应轴伺服系统加速能力范围内,同时控制加加速度分量,以保证在加工中的任意时刻不会出现过大冲击和振动.通过运动学定性分析,设计一种稳定的插补策略修正算法,对曲线状况进行前瞻计算,在发现危险点后灵活、高效地追溯原数据,并对速度曲线进行修正.与同类算法的仿真对比实验表明,该算法能够获得更好的加工特性.

The dynamic influence on each axis will significantly influence the machining stability and product precision while high speed machining （HSM） is significant but always be ignored in most interpolators.The proposed axis-based look-ahead NURBS interpolator （ALANI） not only guarantees the contour precision of workpiece,but also confines the component acceleration according to the capability of the servo system on each axis,restricting the component jerk to avoid immoderate vibration and shocks.Based on the kinematics analysis,an algorithm of interpolation strategy modification was designed,which can efficiently modify the feedrate while encountering a bad point during the look-ahead calculation.The simulation shows that the ALANI algorithm has better characteristic compared to other interpolators.