摘要
针对数控加工中时间最优速度规划光顺性不足的问题,对进给速度规划、高阶运动约束、曲线光顺等方面进行了研究与归纳,提出了一种固定部分区域的能量光顺方法。用B样条曲线表示速度曲线,以机床驱动限制等约束建立了时间最优模型,采用二分迭代的启发式算法获得了加工时间最优速度曲线;考虑到直接光顺会导致违反约束和失去原本的时间最优性的情况,提出了固定速度极小值区域和超限区域进行光顺的策略,建立了固定部分区域光顺的最优模型,并提出了求解方法;利用MATLAB对光顺前后速度曲线的光顺性、时间性、约束符合情况进行了测试。研究结果表明:在满足约束限制和保留大部分时间最优性的情况下,采用该方法后的加加速度平均振荡幅度下降了16.37%,有效改善了速度曲线的光顺性,有利于数控系统的平稳高效运行。
Aiming at the problem of insufficient smoothness in the time optimal feed rate planning of CNC machining,feed rate planning,high-order constraints and curve smoothing were researched,and a method for smoothing the time optimal feed rate curve with fixed areas was proposed.The B-spline curve was used to express the feed rate curve,and the time optimal model was established with constraints such as machine tool driving constraints,and the heuristic algorithm of binary search was used to obtain the optimal feed rate curve of processing time.Considering the situation of violation of feed rate planning constraints and loss of time optimality caused by direct smoothing,a strategy of smoothing with fixed minimum feed rate areas and over-limit areas was proposed.The optimal model for smoothing feed rate curve with fixed areas was established,and the solution method was proposed.The smoothness,processing time,and constraints compliance of the feed rate curve before and after smoothing were tested by using MATLAB.The results indicate that the proposed method improves the smoothness of the speed curve while satisfying the constraints and retaining most of the time optimality,and the average jerk amplitude decreases by 16.37%,which is conducive to high-speed and high-precision processing.
作者
王琦
王桂荣
WANG Qi;WANG Gui-rong(College of Mechanical and Electrical Engineering,China Jiliang University,Hangzhou 310018,China)
出处
《机电工程》
CAS
北大核心
2021年第1期75-80,共6页
Journal of Mechanical & Electrical Engineering
基金
国家自然科学基金资助项目(61640314)。
关键词
NURBS插补
进给速度规划
能量法光顺
高阶约束
数控加工
NURBS interpolation
feed rate planning
curve energy minimization
high-order constraints
computer numerical control(CNC)machining
