Two-Fingered Grasping Position Analysis

• Main Authors: Jen-Wei Huang, 黃振威
• Other Authors: Chao-Hwa Liu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/84434325286344449533

碩士 === 淡江大學 === 機械與機電工程學系碩士班 === 100 === In this thesis the optimum grasping positions for two-fingered grasping of a rigid body is determined. It is known that the inverse dynamics problem has one degree of indeterminacy. In this study a normal force N1 is chosen as the indeterminate force, and all other forces may be expressed as linear functions of this force. For each finger Coulomb’s law of friction is then utilized to determine the region of N1 in which no relative slip occurs. Intersection of the two regions for N1 , one for each finger, is the graspable N1 region. Comparing graspable regions for all possible combinations of contact points, the region with the smallest positive lower limit may be chosen, then the corresponding contact pairs are the optimum grasping positions. Results show that for spherical, rectangular parallelepiped, and cylindrical objects, the optimum grasping positions are antipodal points. When a cubic has a linear acceleration in two directions, the optimum grasping positions are along the intersection of the two planes that are normal to the two linear accelerations. Finally, when a rectangular parallelepiped has both a linear acceleration and an angular acceleration in the same direction, the optimum grasping nodes form a line that is normal to the direction of the acceleration.