一种新型欠驱动机械手爪的抓取分析和优化设计

传统欠驱动机械手的运动和功能单一，难以实现对不同尺寸物体的稳定抓取．为此，提出了一种新型欠驱动手爪结构，并进行抓取分析和优化．首先，介绍了欠驱动机械手爪的整体机构设计，并对手指进行静力学分析，针对手爪包络抓取物体时可能发生弹射的不稳定情况，进行手指结构优化．然后，基于刚度矩阵的势能模型，确定指尖合理的尺寸范围并建立指尖最佳形状．通过几何约束中的数学公式，表达了指尖抓取时手指位姿和物体尺寸的关系．最后，完成手爪样机的搭建，并对常见家用物品进行了指尖抓取和包络抓取实验．实验结果表明，该机械手爪能够对各种尺寸大小的物体进行稳定抓取．

Grasp Analysis and Optimal Design of a New Underactuated Manipulator

Due to the insufficiencies of traditional underactuated manipulator in motion and function, it is difficult to grasp objects of different sizes stably. A new underactuated manipulator structure is proposed, and then the analysis and optimization of grasp are carried out. Firstly, the overall structure design of the underactuated manipulator is introduced, and then the static analysis of the finger is implemented. The structure of the finger is optimized for the instability caused by the ejection when the finger envelopes objects. Then, the reasonable size range of fingertip is determined and the optimal shape of fingertip is established based on the potential energy model of stiffness matrix. The relationship between the manipulator posture and the object sizes is expressed when the fingertips grasp objects by mathematical formula in geometric constraints. Finally, the prototype of the manipulator is built, and the fingertip grasp and envelope grasp of common household goods are carried out, which verifies that the manipulator can grasp objects of various sizes stably.