Development of a Redirection System for Collision Avoidance of “Quad-SCARA” Robot Platform Based on Buffered Voronoi Cell

The authors have developed a platform of four robot arms called “Quad-SCARA” and realized their collaborative manipulation of a handkerchief by Buffered Voronoi Cell (BVC), a powerful collision avoidance algorithm with modifications. These modifications are necessary because BVC is not originally intended for robot arms fixed on a table. Although the modified BVC performs well, there are still some rare cases that robot arms go along incorrect directions, which finally leads to collision. This paper addresses this issue, with its analysis and corresponding solution: redirection. The details of redirection, including the judgement of its appropriate conditions to act and quantitative data about the amount of redirection are also given. Finally, comparison experiments in both simulator and reality validate the capability and indispensability of the proposed redirection system.