仿人手精巧抓取柔性末端结构设计与变形特性研究

为提高机器人柔性末端的适应性、稳定性、精确性和易控性,以圆柱形物体抓取为例设计3种仿人手柔性手爪方案并进行优选;针对仿人手非对称手爪的变形特点,提出包括抓取对象偏心距、末端位移垂直偏差、末端位移水平偏差、柔性手指曲率半径、最小工作压力在内的5个评价指标。通过单指变形特性试验和多指手抓变形特性试验,分析不同状态下的手爪变形规律。研究表明:采用对开式三指布置能有效降低最小工作压力;与长短手指组合相结合后,能有效提高不同压力和负载下的抓取稳定性和精度,并使得手指的曲率半径变化线性度提高。总体上,传统柔性手爪方案手爪的变形非线性较强,负载的增加会使手爪所需的工作压力增大;采用非对称布置的仿人手抓取方案综合性能最优。研究结果为机器人柔性末端结构优化及其形态的精确控制提供了参考依据。

Study on the Structure Design and Deformation Characteristics of Flexible End-effectors with Humanoid Exquisite Grasp Function

In order to improve the adaptability, stability, accuracy and controllability of flexible end effectors of the robot, three kinds of humanoid flexible gripper scheme were designed and optimized by taking a cylinder object grasping as an example.Aimed at the deformation characteristics of the asymmetric hand gripper, the eccentricity of the grab object, the vertical deviation of the end displacement, the horizontal deviation of the end displacement, the curvature radius of the flexible finger and the minimum working pressure were proposed as evaluation indexes.Through single finger deformation characteristic test and multi finger gripper deformation characteristic test, the deformation law of hand gripper under different states was analyzed.The results show that the minimum working pressure can be effectively reduced by using bi parting three finger arrangement; when combined with the finger of different lengths, the grasping stability and accuracy under different pressures and loads are improved obviously, and the linearity of the curvature radius of the finger is improved.Generally, in the traditional flexible gripper scheme, the deformation of the gripper is nonlinear, and the increase of load will increase the working pressure required of the gripper; the humanoid grasping scheme with asymmetric arrangement has the best comprehensive performance. The results provide a reference for the structure optimization and precise control of robot flexible end-effectors.