Joonhaeng Lee


Spherical Deployable Shield for Robot Arm

Advised by Chuck Hoberman

This thesis focuses on the construction of deployable shields for robot arms in extraterrestrial situations that protect them from possible threats by minimizing the area of the robot’s end-effector that is exposed to external job site conditions. The deployability is key since the shield’s shape should be compact, not to hinder the robot’s movement when folded, but also able to adapt to the various geometrical characteristics of the job site when deployed, which could include flat surfaces, curved domes, or even edged areas. To address this necessity and meet those constraints for the shield, this research proposes a deployable spherical shield after exploring a few of the potential possibilities.

The research explores scissor, parallelogram, and spherical linkage patterns as possible ways of creating deployable spherical geometries. Parametric modeling and simulation of those linkages were conducted to analyze deployment movement and possible collision. Ultimately, the research focused on a multilayered spherical linkage construction method that can create a fully covered sphere surface while minimizing overlapping area while it is deployed. Physical prototypes actuated by multiple motors demonstrate how this method can be used to achieve the goal of creating deployable shields that are adaptable and provide full coverage. This research has great potential for robot arm applications in a variety of risky environments, both extraterrestrial and terrestrial. 

Computer images of four aspects each of the collppsible curvedshields.One is a curved scissor arm, one a parallelogram linkage and another uses spherical sections.

Photograph of a spherical model made of nestled plastic pieces and electronic motors wired to the bottom. One side is disassembled and laid out in a line to show the layers of construction.