基于三次多项式加减速的NURBS插补前瞻控制算法  

Look-ahead Interpolation Algorithm for NURBS Curve Based on the Cubic Polynomial Model

作　　者：张力[1,2] 杨东升[1] 王允森[1,2] 李海英[1,2] 

机构地区：[1]中国科学院沈阳计算技术研究所,沈阳110168 [2]中国科学院大学,北京100049

出　　处：《组合机床与自动化加工技术》2014年第3期1-4,8,共5页Modular Machine Tool & Automatic Manufacturing Technique

基　　金："核高基"国家科技重大专项(2012ZX01029-001-002)

摘　　要：为实现数控加工中进给速度、加速度的平滑过渡,减少加加速度急剧变化时机床的振动,提出了一种三次多项式加减速的NURBS曲线前瞻插补算法,该算法包括预处理、前瞻和实时插补。预处理时根据曲线曲率变化找到速度敏感点,然后根据速度敏感点对曲线分段,确定速度敏感点处的最优速度。前瞻时利用三次多项式型加减速对前瞻路径进行规划,防止速度的急剧变化,从而满足机床的加减速性能。仿真实验表明,该算法能够实现曲线的速度、加速度的平滑过渡并减少了加加速度突变次数。To satisfy smooth feedrate and acceleration,reduce shock and vibration impact on machine tools caused by jerk changes,a look-ahead interpolation algorithm for NURBS curve,including interpolation preprocess,look-ahead and real-time interpolation,is proposed,and the speed velocity was also constructed by the cubic polynomial,During interpolation preprocess,the curve is dividing into some segments according to the different curvature movement.After that the high speed of the federate sensitive corners is established to satisfy the system and the given federate.During the look-ahead process,the federate between sensitive points are set up based on the cubic polynomial acceleration and deceleration control model.In order to obtain a continuous velocity and satisfy the acceleration and deceleration performance of machine tools accelerating profile were found out which reduced the jerk relate problem.By the results of simulations,it demonstrated that this algorithm can get a smooth feedrate,accelerate profile and jerk profile,also reduce the frequency of jerk mutations.

关 键 词：前瞻算法 三次多项式加减速 NURBS 

分 类 号：TH164[机械工程—机械制造及自动化] TG68[金属学及工艺—金属切削加工及机床]