An ultraprecision positioning system using twist-roller friction drive

采用扭转滚子摩擦驱动的超精密定位系统

基本信息

批准号：
13650252
负责人：
MIZUMOTO Hiroshi
金额：
$ 2.62万
依托单位：
Tottori University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650252/
关键词：
Piezoelectric actuator Positioning Machine tool Rolling friction Nanotechnology Picometer Friction drive Mechatronics ピコメータ

项目摘要

The twist-roller friction drive mechanism is a kind of lead screw having a small lead. It was reported that the positioning resolution of a positioning system using the twist-roller friction drive mechanism is as small as 0.2nm, where an AC servomotor was used as the actuator. In the present research, instead of the servomotor, a piezoelectric actuator with motion reduction mechanism is used, and the limitation of the positioning resolution of the twist-roller friction drive mechanism is investigated. The motion reduction mechanism can be regarded as a precise linear converter of the actuator deformation to the table displacement. The reduction ratio of the mechanism is less than two-thousandth.The displacement of the table is detected by a fiber-optic sensor. Nominal resolution of this fiber-optic sensor is 0.25nm in the frequency range to 130kHz. With external low-pass filtering, finer resolution can be obtained. Detected table movement is fed back to a microcomputer that controls the supply voltage for the piezoelectric actuator. Thus a closed-loop control system for the table positioning is realized. The LSB (Least Significant Bit) of the digital control system is 76pm, which is larger than the positioning resolution to be investigated. For the precise control less than the LSB, PNM (Pulse Number Modulation) is employed in the controller. Cycle time of the control system is about 30μs.Experiments of step positioning using the closed-loop control system shows that steps of 1nm, 0.5nm and 0.1nm are clearly resolved. However, the noise level is almost equal to the step width and the limitation of the positioning resolution is considered to be 50pm. Because of the linearity of motion conversion and high repeatability in nanometer range, the twist-roller friction drive mechanism can control the table position precisely and can be used as a picometer-positioning device for improving the ultraprecision machining and measurement.

旋转摩擦驱动机构是一种具有较小铅的铅螺钉。据报道，使用扭转摩擦驱动机制的定位系统的定位分辨率小至0.2nm，其中AC伺服电机被用作执行器。在本研究中，使用具有运动还原机制的压电执行器，而不是伺服电机，并研究了扭曲旋转摩擦驱动机制的定位分辨率的局限性。运动还原机制可以被视为执行器变形到表位移的精确线性转换器。机制的降低比小于千分之二。桌子的位移由光纤传感器检测到。该光纤传感器的标称分辨率在频率范围为130kHz的0.25nm。通过外部低通滤波，可以获得更精细的分辨率。检测到的表移动被馈回微型计算机，该微型计算机控制压电执行器的电源电压。实现了用于表定位的闭环控制系统。数字控制系统的LSB（最少显着）为76pm，比要研究的定位分辨率大。对于小于LSB的精确控制，PNM（脉冲数调制）在控制器中携带。控制系统的循环时间约为30μ。使用闭环控制系统的步骤定位的示例表明，清楚地解决了1NM，0.5nm和0.1nm的台阶。但是，噪声水平几乎等于步长，定位分辨率的限制被认为是下午50点。由于运动转换的线性和纳米范围内的高可重复性的线性性，扭曲旋转摩擦驱动机制可以精确控制表位置，并可以用作可改进超压缩加工和测量的生态表位置设备。