Hierarchical distributed architectures for autonomous mobile robots: A case study

Robots are becoming commonplace in unstructured and dynamic environments, ranging from homes to offices, public sites, catastrophe sites, military scenarios. Achieving adequate performance in such circumstances requires complex control architectures, mixing adequately deliberative and reactive capabilities. This mixing needs to be properly addressed from both the software and hardware architectures point of view and, particularly, the mapping of the former onto the latter, in order to reduce mutual interference between concurrent behaviors and support the desired coordination with adequate level of reactivity. This paper discusses the benefits of using hierarchical distributed hardware architectures and presents the case study of the CAMBADA soccer robots developed at the University of Aveiro, Portugal. These robots use a distributed hardware architecture with a central computer to carry out vision sensing, global coordination and deliberative functions and a low-level distributed sensing and actuation system based on a set of simple microcontroller nodes interconnected with a Controller Area Network (CAN).