A two-phase gripper to reorient and grasp
A two-phase gripper to reorient and grasp
复制标题
用于重新定向和抓取的两相夹具
DOI：
10.1109/coase.2015.7294269
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Alberto Rodriguez
中科院分区：
文献类型：
--
作者：
Nikhil Chavan Dafle;M. T. Mason;H. Staab;Gregory F. Rossano;Alberto Rodriguez
本文介绍了新型两相手指的设计，可在拾取物体时被动地重新定向。两相是指随着夹持力的增加，手指-物体接触几何形状的变化，从自由旋转的点接触到牢固的多点接触。我们利用这两个阶段来被动地将棱柱形物体从水平静止姿势重新定向为直立安全抓握。这个问题与工业装配应用尤其相关，在工业装配应用中，零件通常放置在托盘或传送带上，并且需要垂直组装。每个两相指状件均由一个小的硬接触点组成，该接触点连接到安装在 V 形槽腔上方的弹性条上。当以低夹持力抓住两个平行的手指时，物体绕条带上的接触点之间的轴线枢转，并在重力作用下垂直对齐。随后抓握力的增加使弹性条退回到空腔中，使零件固定在 V 形槽中以固定抓握。该设计与任何类型的平行爪夹持器兼容，并且可以通过改变腔体的几何形状来重新配置以适应特定的物体。两相夹具为机器人提供了精确定位和操纵零件的能力，减少了对专用零件送料器或耗时的重新抓取程序的需求。
This paper introduces the design of novel two-phase fingers to passively reorient objects while picking them up. Two-phase refers to a change in the finger-object contact geometry, from a free spinning point contact to a firm multipoint contact, as the gripping force increases. We exploit the two phases to passively reorient prismatic objects from a horizontal resting pose to an upright secure grasp. This problem is particularly relevant to industrial assembly applications where parts often are presented lying on trays or conveyor belts and need to be assembled vertically. Each two-phase finger is composed of a small hard contact point attached to an elastic strip mounted over a V-groove cavity. When grasped between two parallel fingers with low gripping force, the object pivots about the axis between the contact points on the strips, and aligns upright with gravity. A subsequent increase in the gripping force makes the elastic strips recede into the cavities letting the part seat in the V-grooves to secure the grasp. The design is compatible with any type of parallel-jaw gripper, and can be reconfigured to specific objects by changing the geometry of the cavity. The two-phase gripper provides robots with the capability to accurately position and manipulate parts, reducing the need for dedicated part feeders or time-demanding regrasp procedures.