基于宏微组合驱动方式,提出一种具有角度修正功能的大行程二维纳米工作台设计方案来减小精密测量系统中由于工作台定位及角度误差引入的测量误差。首先,从原理上对设计方案进行了论证。该方案中宏动工作台和微动工作台共用位置反馈系统构成闭环控制,并基于压电陶瓷致动器及柔性铰链设计的六自由度微动工作台对宏动工作台进行直线定位误差及角度误差的综合补偿。然后,基于设计方案设计了宏动工作台及微动工作台的结构。最后,对安装调试后的宏微工作台系统进行了直线组合定位测试及角度误差修正测试。实验结果表明,该工作台系统的宏动行程达到了200mm×200mm;在闭环控制下,通过六自由度微动工作台的补偿作用可使各角度偏差由上百秒降至10″以内,由此工作台系统在全行程内的直线定位误差可由3μm降至25nm以内。实验结果验证了提出的组合定位系统的有效性。
On the basis of a macro-micro dual driven method,a solution for the large stroke 2-DOF nano-positioning stage with angle error correction functions is proposed to reduce the measurement errors in a precision measurement system caused by positioning and angular errors of the stage.Firstly,the principle of the solution is demonstrated.In this solution,the macro stage and micro stage share the same position feedback systems to form a closed loop control,and both linear positioning errors and angle errors of macro stage are compensated with the help of a 6-DOF micro stage based on a piezoelectric ceramic actuator and a flexible hinge.Then,the macro stage and micro stage are designed and manufactured based on the solution.Finally,the performance of the 2-DOF nano-positioning stage with error correction functions are tested preliminarily.Experimental result indicates that the stroke of the 2-DOF nano-positioning stage reaches 200 mm×200 mm.With the correction of the micro stage under the closed-loop control,all of the angle errors of the stage are reduced from hundreds of seconds to less than 10″,and the positioning error is reduced from 3 μm to less than 25 nm.Experimental result verifies the effectiveness of the macro-micro dual positioning system.