A Case Study of Flexible Object Manipulation

摘要

This article describes a project undertaken to explore pro gramming physical operations on complex flexible objects. Uncertainty about the exact state of the object makes it im possible to precisely specify the actions to be performed at the time the program is written. Furthermore, the detailed conse quences of manipulations on flexible objects cannot be deter mined before the action is performed. Lacking precise specifi cations, the programmer must abstract the essential properties of objects and actions. In an effort to study manipulation offlexible objects, a system to tie knots in rope with a robot arm was developed. The system includes an extensible graph representation for knots, a vision system that binds the contour of a physical rope to an abstract description, and a knot-tying language based on parametric motion commands. Knots of modest complexity, such as a bowline or figure 8, can be tied in a va riety of ropes with minimal constraints on the initial configu ration of the rope. The work highlights the importance of software engineering principles and a good programming en vironment for robot program development.