Topology optimization is an effective method for the lightweight of collaborative robots. The extreme working conditions of the robot for the existing topology optimization approach are usually determined by design experience, which may cause mismatch between the chosen load boundary condition of the parts to be optimized and the actual maximum one. In this article, a kind of topology optimization method based on orthogonal experiment was proposed to avoid this mismatch. For this method, the extreme working condition of robots was determined by finding out the combination of robot joint angles when the stress of the part was maximum based on orthogonal experiment. And then, the structure of the part was optimized with the objective of minimizing mass and the constraint of the maximum end displacement of the robots. Finally, the proposed method and the existing method were applied to the lightweight design of a 7 degree of freedom upper limb powered exoskeleton robot, and the results demonstrated that the presented approach can reduce 6.78% maximum end displacement of the robot on average compared with the existing one. It can be concluded that the proposed method in this article is more reasonable and applicable to the structure optimization of collaborative robots.

拓扑优化是协作机器人轻量化的有效方法。现有拓扑优化方法的机器人极限工作条件通常是由设计经验决定的，这可能会导致所选择的待优化部件的载荷边界条件与实际最大载荷边界条件不匹配。本文提出了一种基于正交实验的拓扑优化方法来避免这种不匹配。该方法通过正交试验，找出零件应力最大时机器人关节角度的组合，确定机器人的极端工作状态。然后，以质量最小化和机器人最大末端位移约束为目标，对零件结构进行了优化。最后，将所提出的方法和现有方法应用于7自由度上肢动力外骨骼机器人的轻量化设计，结果表明，与现有方法相比，所提出的方法平均可以减少机器人的最大末端位移6.78%。 . 可以得出结论，本文提出的方法更加合理，适用于协作机器人的结构优化。