目的 为了设计出具有x，y和z方向纯平动的微纳级精密定位装置。方法 首先，运用旋量与逆螺旋理验证所设计的传统3-UPU并联机构运动特性；采用封闭矢量映射原理构建3-UPU并联机构的微分Jacobian，实现各关节与动平台的空间映射关系。然后，定义优化问题的目标函数为结构刚度，约束函数为体积比，运动特性条件为微分Jacobian构造3-UPU柔顺并联机构的SIMP模型，并运用优化算法计算。最后，基于Ossmooth对优化构型进行CAD模型的提取，完成运动特性的力学仿真分析，此外，通过3D打印制造处理后的CAD模型，并完成运动特性的实验测试。结果 仿真可得，优化后的构型柔度值从58.324 mm/N下降到25.993 mm/N；一阶固有频率从964.64 Hz提高到1362.26 Hz；沿x，y和z方向的微运动特性分别达到2.488，6.512，9.185 μm；3-UPU柔顺并联机构优化构型的微运动特性与理论解处于同一微米级，并运用实验测试进行了验证。结论 拓扑优化设计的构型具有微米级运动特性和微米定位精度，实验测试结果验证了该优化技术的可行性。

The work aims to design a micro-nano precision positioning device with pure translational motion along x, y and z direction. Firstly, the screw and reciprocal screw theory were used to verify the kinetic characteristic of the designed traditional 3-UPU parallel mechanism. The closed vector mapping principle was adopted to construct the differential Jacobian of 3-UPU parallel mechanism to realize the spatial mapping relation between the joints and the moving platform. Then, the objective function used to optimize problem was defined as structural stiffness and constraint function as the volume ratio. The kinetic characteristic condition was the SIMP model of 3-UPU compliant parallel mechanism built by differential Jacobian and solved by optimization algorithm. Finally, the CAD model was extracted for optimized configuration based on Ossmooth, and the mechanical simulation analysis of the kinetic characteristics was completed. Furthermore, the processed CAD model was produced by 3D printing, and the experimental test of kinetic characteristics was completed. Through simulation, the compliance value of the optimized configuration declined from 58.324 mm/N to 25.993 mm/N, the first order natural frequency increased from 964.64 Hz to 1362.26 Hz, the micro kinetic characteristics along x, y and z direction reached 2.488, 6.512 and 9.185 μm respectively and the micro kinetic characteristics of the optimal configuration of 3-UPU compliant parallel mechanism was at the same micron level as the theoretical solution, which was verified by experimental test. Configuration of the topological optimization design has micron kinetic charac-teristics and micron positioning accuracy, and the feasibility of the optimization technique is verified by the experimental results.