用于六轴联动数控电火花加工的广义单位弧长增量插补法  

Generalized Unit Arc Length Increment Method for Six-axis Electro-discharge Machining

作　　者：陈默[1] 陈昊[1] 奚学程[1] 赵万生[1] 

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《电加工与模具》2015年第3期1-7,共7页Electromachining & Mould

基　　金：国家自然科学基金资助项目(51175337);机械系统与振动国家重点实验室资助项目(MSVMS201111)

摘　　要：针对复杂形状型腔零件的电火花成形加工中以参数曲线形式所描述的运动轨迹,在单位弧长增量法的基础上,研究了由参数曲线表达式直接生成各轴进给脉冲的多轴联动轨迹精插补方法——广义单位弧长增量法。该方法以脉冲当量作为各轴统一单位,将直线轴运动视为一个合成运动、每个旋转轴运动视为一个独立运动,各运动之间通过弧长比例决定插补进度,并将最长运动的每步弧长增量取定为一个脉冲当量,使每个插补周期内每个轴的运动量不大于一个脉冲当量,可将插补误差控制在与机床分辨率所决定的最小单位长度相近的范围内。仿真实验结果表明:该算法与传统的数据采样法相比,能以较小的存储空间消耗量达到较高的插补精度。最后,通过闭式整体叶盘的成形加工实验验证了该算法的稳定性和可靠性。Parametric curves can describe the tool paths in electro-discharge machining （EDM） of the cavities of complex shape. The generalized unit arc length increment （GUALI） method is given as a fine interpolation method for direct generation of axis pulses for multi-axis machining. The basic length unit （BLU） is taken as the unit of each axis position. The composition of all motions of the linear axes is regarded as a composite motion,while the motion of a rotary axis is still regarded as one independent motion. The interpolation progresses of all motions are determined by the proportional relationships between the arc lengths of the motions. The arc length increment of each step for the motion with the largest arc length is assigned to be 1 BLU ,and thus the position increment of each axis in each interpolation period is no larger than 1 BLU. Therefore ,the interpolation errors can be kept around the minimum position increment of an axis. Simulation results show that higher accuracy can be reached with less memory consumption by the GUALI method compared to the sampled data method. The stability and reliability of the GUALI method is verified by the EDM of a shrouded turbine blisk.

关 键 词：电火花成形加工 参数曲线 插补 多轴联动 

分 类 号：TG661[金属学及工艺—金属切削加工及机床]