Workspace Characterization for Hybrid Tendon and Ball Chain Continuum Robots.

Continuum robots have attracted considerable attention for applications in minimally invasive diagnostics and therapeutics over the past decade [1]. The primary reason is their ability to navigate narrow and tortuous anatomical passageways, while guaranteeing safe inter- action with the anatomy. In designing such robots, an important goal is create a robot with a workspace appropriate for the clinical task. A significant limitation of many continuum designs re- lates to the minimum radius of curvature that a particular design can achieve. While multiple bending sections can be concatenated to provide more degrees of freedom, the orientations by which a point in the workspace can be approached are often limited. To overcome this limitation, this paper investigates a hybrid design that combines the advantages of tendon- actuated [2] and magnetic ball chain robots [3] as shown in Fig. 1. In this hybrid design, a proximal tendon- actuated section positions the robot with respect to the goal tip location while a distal ball chain section orients the robot tip with respect to the goal location. This abstract describes how the hybrid kinematics can be modeled and illustrates how the hybrid design possesses a dextrous workspace of finite extent.