Control of Grip Force When Tilting Objects: Effect of Curvature of Grasped Surfaces and Applied Tangential Torque
Control of Grip Force When Tilting Objects: Effect of Curvature of Grasped Surfaces and Applied Tangential Torque
复制标题
倾斜物体时夹持力的控制：夹持表面曲率和施加切向扭矩的影响
作者：
A. Goodwin;Per Jenmalm;R. Johansson
当我们在日常任务中操纵物体时，抓取表面的形状会发生变化，并且可能使抓取不稳定的负载包括与抓取表面相切的随时间变化的线性力和扭矩。以往的研究指尖的把握稳定性的控制力主要处理与平坦的抓地力表面和线性力负荷。在这里，我们研究了当人类举起物体并绕水平握持轴旋转65°角时，随着握持表面曲率的变化以及食指和拇指施加的切向扭矩的变化，握持力的调节。匹配的球面对的曲率从−50 m−1（半径为20 mm的凹面）到200 m−1（半径为5 mm的凸面）不等。在65°方向施加的切向扭矩变化6倍。无论曲率和末端扭矩的值如何，握力和切向扭矩都是协调的，在整个倾斜过程中以近似线性关系平行增加;线的斜率随着表面曲率的增加而逐渐增加。夹持力的参数缩放与防止旋转滑动所需的最小夹持力直接相关，从而在所有情况下都有足够的安全裕度防止滑动。我们的结论是，表面曲率参数影响握力调节时的数字是暴露在扭转载荷。此外，控制抓握力的感觉运动程序显然预测了包括线性力和切向扭矩的总负荷的影响。
When we manipulate objects in everyday tasks, there are variations in the shape of the grasped surfaces, and the loads that potentially destabilize the grasp include time-varying linear forces and torques tangential to the grasped surfaces. Previous studies of the control of fingertip forces for grasp stability have dealt principally with flat grip surfaces and linear force loads. Here, we studied the regulation of grip force with changes in curvature of grasped surfaces and changes in tangential torque applied by the index finger and thumb when humans lifted an object and rotated it about the horizontal grip axis through an angle of 65°. The curvatures of the matched pair of spherical surfaces varied from −50 m−1 (concave with radius 20 mm) to 200 m−1 (convex with radius 5 mm). The applied tangential torque at the orientation of 65° was varied sixfold. Regardless of the values of curvature and end torque, grip force and tangential torque were coordinated, increasing in parallel throughout the tilt with an approximately linear relationship; the slope of the line increased progressively with increasing surface curvature. This parametric scaling of grip force was directly related to the minimum grip force required to prevent rotational slip, resulting in an adequate safety margin against slip in all cases. We conclude that surface curvature parametrically influences grip force regulation when the digits are exposed to torsional loads. Furthermore, the sensorimotor programs that control the grip force apparently predict the effect of the total load comprising linear forces and tangential torques.
单关节和多关节手臂运动中的姿势控制和轨迹形成。
影响因子：
--
作者：
Bizzi,E;Abend,W
通讯作者：
Abend,W
DOI：
10.1115/1.2795945
发表时间：
1996-02-01
影响因子：
1.7
作者：
Srinivasan, MA;Dandekar, K
通讯作者：
Dandekar, K