基于三阶变频控制的亚微米工件台定位方法研究  

Research on positioning method of submicron work-stage based on three-times varying frequency control

作　　者：曾环 田鹏[1] 郭潇逸 陆小龙[1] 林思建 Zeng Huan;Tian Peng;Guo Xiaoyi;Lu Xiaolong;Lin Sijian(School of Mechanical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学机械工程学院,成都610065

出　　处：《电子测量技术》2020年第23期73-77,共5页Electronic Measurement Technology

基　　金：四川大学博士后交叉学科创新培育项目(2019BHJX11);四川省科技厅创新创业苗子工程重点项目(2019JDRC0094)资助。

摘　　要：微细加工光学技术要求工件平台具有纳米级定位精度,其中初级高速大行程步进电机运动系统精度需突破1μm。受限于电机丢步和机械惯性两个不利因素的影响,现有的闭环控制方法难以满意精度要求或者控制过程复杂不利于系统集成。提出反向利用这两个因素进行变频控制的闭环定位方法,MCU根据上位机指令计算脉冲频率和总数,并利用内部计数器对脉冲进行计数,一阶高频脉冲迅速靠近,计数溢出后平台为欠定位,二阶低频脉冲逼近,计数溢出后平台为过定位,三阶超低频脉冲使平台在定位点循环微振动至定位结束。实验采用五相步进电机和光栅尺构建50 nm分辨率的闭环运动控制平台,连续正向和反向定位数据表明该方法稳定性和重复性好,定位精度可达300 nm。Nano-level positioning accuracy is required for work-stage in the optical technologies for microfabrication. In which the precision of high-speed large-stroke stepping motor motion system needs to exceed 1 μm. Limited by the two disadvantages of motor stepping-loss and mechanical inertia, the existed closed-loop methods are difficult to meet the accuracy requirement or not conducive to the system integration because of the complex control process. The two factors are used reversely as the parameters for the frequency conversion control in the closed-loop positioning. The pulse frequency and amount are calculated by the MCU refer to the commands of the computer program and an internal counter is utilized to count the pulses. The first-order, work-stage is under-positioning at the counting overflow which approaching the destination by a high frequency pulse. The second-order, it’s over-positioning that getting closer by a low frequency pulse similarly. The third-order, it vibrates slightly and circularly at the aim point until the end of positioning using the lowest frequency pulse. Here, a 50 nm resolution closed-loop motion control platform was constructed with five-phase stepping motors and grating rulers. The continuous forward and reverse positioning experiments showed that the method had the fine stability and repeatability, and the positioning accuracy was up to 300 nm.

关 键 词：步进电机 闭环控制 亚微米 

分 类 号：TP271.8[自动化与计算机技术—检测技术与自动化装置]