A polyhedral bound on the indeterminate contact forces in 2D fixturing and grasping arrangements
A polyhedral bound on the indeterminate contact forces in 2D fixturing and grasping arrangements
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二维固定和抓取装置中不确定接触力的多面体边界
DOI：
10.1109/robot.2003.1241859
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
T. Omata
中科院分区：
文献类型：
--
作者：
E. Rimon;J. Burdick;T. Omata
本文考虑二维接触布置，其中多个物体通过摩擦点接触来抓取、固定或支撑一个物体。在严格的刚体建模范例中，当外部扳手(即力和扭矩)作用于对象时，接触处的反作用力是不确定的，并且跨越无限的线性空间。本文分析了准刚体框架内的接触力，它既保持了刚体建模所需的几何特性，又包含了更逼真的物理效果。利用准刚性接触力学的两个原理，我们证明了对于作用在物体上的任何给定的外扳手，接触力位于有界多面体集中。多面体边界取决于外扳手、抓手的几何形状和预紧力。但它不依赖于接触力学参数的任何详细知识。该边界对于“稳健”的抓取和夹具综合是有用的。给定一组可能作用于物体的外扳手，可以选择抓握的几何形状和预紧力，以便所有这些外扳手都将自动由触点支撑。
This paper considers 2D contact arrangements where several bodies grasp, fixture, or support an object via frictional point contacts. Within a strictly rigid body modelling paradigm, when an external wrench (i.e. force and torque) acts on the object, the reaction forces at the contacts are indeterminate and span an unbounded linear space. This paper analyzes the contact forces within a quasi-rigid body framework that keeps the desirable geometric properties of rigid body modelling, while also includes more realistic physical effects. Using two principles governing the mechanics of quasi-rigid contacts, we show that for any given external wrench acting on the object, the contact forces lie in a bounded polyhedral set. The polyhedral bound depends on the external wrench, the grasp's geometry, and the preload forces. But it does not depend on any detailed knowledge of the contact mechanics parameters. The bound is useful for "robust" grasp and fixture synthesis. Given a collection of external wrenches that may act on an object, the grasp's geometry and preload forces can be chosen such that all of these external wrenches would be automatically supported by the contacts.