Transportation of long objects in unknown cluttered environments by a team of robots: a dynamical systems approach

We present a distributed architecture for teams of two autonomous mobile robots that act in coordination in a joint transportation task of long objects. The team is able to perform its transportation task in unknown environments while avoiding static or moving obstacles. The working environment can be cluttered and with narrow passages such as corridors, corners and doors. These characteristics make our approach suitable to be deployed in warehouses or office-like environments. The control architecture of each robot is formalized as a non-linear dynamical system, where by design attractor states dominate. The overt behavior is smooth and stable, because it is generated as a time sequence of attractor states, for the control variables, which contributes to the overall asymptotically stability of the system that makes it robust against perturbations. We present results with real robots in a real indoor cluttered environment.This work is also supported by FEDER Funds through Competitivity Factors Operational Program - COMPETE and National Funds by FCT Portuguese Science and Technology Foundation under the Project FCOMP-01-0124-FEDER022674. We would like to thank all the people that work in our laboratory, MARL (Mobile and Anthropomorphic Robotics Laboratory) at University of Minho. All of them contributed in several ways for the success of this work. Toni Machado would also like to thank the Portuguese Science and Technology Foundation for providing his Ph.D. scholarship (ref. SFRH/BD/38885/2007)