A Control System for a Tool Use Robot: Drawing a Circle by Educing Functions of a Compass

Abstract

[abstFig src='/00290002/12.jpg' width='260' text='Axes in the compass coordinate system' ] Robotic tool use is one of various approaches for actualizing versatility of robots, and is thus the focus of many studies. However, selection of the controllers for tool use and how to design them remains indeterminate. This paper addresses the task of drawing a circle with a compass as an example of tool use. This task mandates to deal with complex contact at multiple points and needs to educe functions of the compass to draw a circle accurately. This paper demonstrates the implementation and corresponding method of compass controller design. The method of designing the controller for the compass entails decomposing the usage of the compass into semantic units and subsequently defining a coordinate system and fabricating the controller via mapping of the semantic units to axes. The implementation of a controller for compass use indicates that the ability of the compass to accurately draw a circle is educed via mechanical constraints of the compass. We validated the implemented controller by drawing a circle and comparing the result to a circle drawn using a pencil.