Multirobot coordination in pick-and-place tasks on a moving conveyor

This paper considers the problem of multirobot coordination in pick-and-place tasks on a conveyor band. The robot team is composed of identical robots with mutually exclusive, but neighboring workspaces. The products are fed in at one end of the band, move through each workspace sequentially until being picked up and are collected at the other end—if not picked up interim. Each robot has the same task—that is picking up and packaging as many products as possible. We propose an approach based on noncooperative game theory where each robot uses local observations of the conveyor band and their neighbors' actions in order to decide on its actions. The developed algorithm has been implemented and tested in a simulated manufacturing environment using Webots. Results obtained from the simulations are analyzed using a variety of statistical performance measures.

► We propose a novel approach for the coordination of a set of robots that pick products moving through their workspace in parallel with their teammates. ► The robot team is composed of identical robots with mutually exclusive, but neighboring workspaces while the products are fed at one end of the band, move through each workspace sequentially if not picked up. ► Each robot, once it completes one pick-up, decides on its next action based on a cost function that embodies its observations of its workspace and those of its neighbors as well as the neighbors' actions. ► The mathematical model of this approach is formulated along with the associated algorithm that is then applied in various scenarios comprising a conveyor band and a multirobot team. ► The advantages of this approach are real-time applicability with simple programming requirements and flexible integration while allowing all the robots to work in all parts of their workspaces.