基于RT-Linux的聚晶金刚石刀具五轴电火花刃磨数控系统  

Five-axis CNC System Based on RT-Linux for Electrical Discharge Grinding Polycrystalline Diamond Tools

作　　者：史少华[1,2] 樊文刚[1,2] 叶佩青[1,2] 张辉[1,2] 方晨曦[1,2] 

机构地区：[1]清华大学机械工程系,北京100084 [2]清华大学精密超精密制造装备及控制北京市重点实验室,北京100084

出　　处：《应用基础与工程科学学报》2014年第1期179-188,共10页Journal of Basic Science and Engineering

基　　金：十二五"高档数控机床与基础制造装备"科技重大专项(2011ZX04004-012);中国博士后科学基金(2012M510423);精密超精密制造装备及控制北京市重点实验室开放课题基金(PMEC201210)

摘　　要：针对聚晶金刚石刀具特殊加工需求,设计和实现了基于RT-Linux的五轴电火花刃磨专用数控系统.系统硬件以PC为上位机,以自主研发的总线式电火花控制硬件为下位机,软件则将实时任务与非实时任务分开,并放入RT-Linux不同内核中,以保证系统的实时性.为解决聚晶金刚石刀具加工轨迹不能预先给出的问题,开发了自适应的刀具形状在线检测模块,实现了基于三次非均匀有理B样条的加工程序自动生成的功能,设计了根据当前放电参数预测腐蚀量确定下一周期插补速度的运动控制模块.对两种典型聚晶金刚石刀具进行加工实验,结果表明系统运行稳定,在50倍放大镜下刀具刃口平滑,外圆径向跳动均在0.01mm以内,满足实际生产对质量和精度的要求.A new five-axis Computer Numerical Control （CNC）system of Electrical Discharge Grinding（EDG） based on RT-Linux is implemented for the special requirements of machining complex PolycrystaUine Diamond （PCD）tools. The hardware of the system is composed of an industrial PC and a self-developed motion-control card with bus-based structure. To ensure the real-time performance, the real-time tasks and non-real-time tasks were separated into different kernels of RT-Linux. Based on the fact that the processing tracks of PCD tools cannot be defined in advance, an adaptive online tool shape detecting module and an automatic programming module based on cubic non-uniform rational B-spline were developed. At the same time, motion control module with the function of predicting the velocity of next interpolation cycle according to the current discharge paranleters was designed in the system. The results of grinding two typical types of polycrystaUine diamond tools showed the stability of the system. The processed cutting edges had good quality observed under a magnifying glass（50X）and the radial vibration was less than 0. 01mm , which can fully meet the requirements on quality and accuracy in actual production.

关 键 词：RT-LINUX 聚晶金刚石刀具 五轴 电火花刃磨 数控系统 

分 类 号：TG661[金属学及工艺—金属切削加工及机床]