二维解耦柔性精密定位平台设计

The Design of a 2D Decoupled Compliant Precision Positioning Stage

设计了一款基于压电陶瓷和柔性铰链的二维解耦精密定位平台,平台采用对称布置的双平行四杆复合机构实现解耦。基于Awtar模型,对平台载荷-位移关系进行分析,推导出平台在X、Y方向上的位移及耦合位移表达式。ANSYS有限元仿真表明,最大耦合发生在平台最大为一处。在平台位移最大时,理论计算的耦合误差达到最大,为0.39%。这与有限元仿真分析得到的0.33%的结果接近。最后,利用显微视觉测量方法对平台X和Y方向的耦合误差进行了实验测试,实验结果表明,耦合误差随着平台运动位移的增大而增大,最大值为1.8%,与理论仿真趋势吻合。

A decoupled 2D precision positioning stage using flexible hinges and driven by piezoelectric actuators are presented. The symmetrical double compound parallelogram flexures areemployed in order to achieve motion with minimum coupling along x and y axes. The force-displacement relationship of the stage is analyzed usingAwtar model and the analytical models for displacement and cross-coupling error in XY directions are derived. The results of finite element simulation （ FEA ） show that the maximum cross-coupling error occurs at the maximum displacement of the stage. Using the derived analytical model, the calculated maximum cross-coupling error is 0.39% when the stage reaches its maximum displacement, which is close to that of 0.25% obtained using FEA simulation. Finally, a series of experiments areimplemented to measure the cross- coupling error by micro-visionmeasurement method. The experimental results show that the cross-coupling error increases with the increasing displacement, which is consistent with that of the analytical model and FEA simulatiomThe measured maximum cross-coupling error is 1.8%for the stage.