抓取过程中的手部运动变形特征

Deformation Characteristics of Hand Movement During Grasping

目的基于多相机数字图像相关(digital image correlation,DIC)方法研究人手在抓取运动中的动态变形特征。方法搭建连续型四相机DIC系统,测量抓取过程中手背皮肤的表面应变,再通过皮肤、关节、骨骼和肌肉之间的联系,间接掌握手部肌肉的变形规律。结果测量中等圆柱抓取、横向捏取、食指伸展抓取以及强力球体抓握4种抓取姿态,发现不同抓取姿态下手背表面不同位置的应变增幅不同,其中最大主应变范围为0.1~0.3。通过分析可以得到手部各肌肉群在不同抓取姿态下的运动特点。结论该方法具有非接触、全场化、结果直观等特点,为抓取过程中动态变形的在体测量提供了一种新途径。

Objective Based on the multi-camera digital image correlation( DIC) method, the dynamic deformation characteristics of human hand during grasping were studied. Methods A continuous four-camera DIC system was established to measure surface strain of the skin on the back of the hand during grasping process,and then through the connection between skin,joints,bones and muscles,the regular pattern of muscle deformation could be known indirectly. Results Four grasping postures( medium cylinder,lateral pinch,index finger extension,power sphere) were measured. It was found that the increases of strain magnitude were different at different positions on back surface of the hand under different grasping postures,and the maximum principal strains were between 0. 1 and 0. 3. The movement characteristics for each muscle group of the hand under different grasping postures were obtained through analysis. Conclusions This method has the characteristics of non-contact,full field,intuitive results,which provides a new way for in vivo measurement of dynamic deformation during grasping.