平面3自由度柔顺微动机器人加工误差分析

在微/纳米级定位领域,误差分析是提高微动机器人运动精度的重要方法.其中,对加工误差的分析尤其关键.为此,对平面3自由度(DOF,Degree of Freedom)柔性并联微动机器人的加工误差进行了研究.通过对机器人静刚度求解,建立了加工误差与其末端执行器定位精度的关系模型.通过理论计算途径及有限元方法(FEM)讨论了各结构参数加工误差对末端精度的影响程度,结果表明柔性铰链圆弧切口半径误差以及铰链圆弧切口中心线角度偏差对机器人末端精度的影响最大.研究所得结论可用于指导此类机构设计,确定加工过程中各机构参数的公差要求,并有助于提高标定精度.

Manufacturing error analysis of compliant planar 3-DOF micro robot

In the fields of micro/nano positioning application, error analysis is an effective way to enhance the precision of such micromanipulators. Manufacturing imperfections, which are inevitable, are the most important factors influencing the accuracy. Thus, various manufacturing errors were studied by taking a planar 3-DOF(degree of freedom) flexure hinge-based micro robot as a case. By means of formulating static stiffness of the robot, mapping between manufacturing imperfections and end-effector positioning accuracy was obtained. Based on theoretical calculation and finite element method, effects of various machining imperfection types on end-effector positioning accuracy were evaluated. The results show that errors of the radius of the hinges and angular differences of the center line of the hinges are dominant factors resulting in output errors. Conclusions drawn from experiments can instruct the design of compliant parallel mechanisms by distributing various configurable parameters' manufacturing differences to ensure the output precision of the end effector within required range; they may also be helpful while calibrating this kind of manipulators.