Reducing Communication Delay Variability for a Group of Robots

A novel architecture is presented for reducing communication delay variability for a group of robots. This architecture relies on using three components: a microprocessor architecture that allows deterministic real-time tasks; an event-based communication protocol in which nodes transmit in a TDMA fashion, without the need of global clock synchronization techniques; and a novel communication scheme that enables deterministic communications by allowing senders to transmit without regard for the state of the medium or coordination with other senders, and receivers can tease apart messages sent simultaneously with a high probability of success. This approach compared to others, allows simultaneous communications without regard for the state of the transmission medium, it allows deterministic communications, and it enables ordered communications that can be a applied in a team of robots. Simulations and experimental results are also included

RISC-based architectures for multiple robot systems

Several approaches to multiple robot system control are discussed. In order to simplify the study a multilayered model is proposed: a control layer which directly acts on the dynamics of the manipulators, a coordination/communication layer which makes all the manipulators work together and a programming layer which interfaces with the user. For the first layer two architectural alternatives are studied: a centralized single processor system and a distributed multiprocessor with static task assignment. For the second case an implementation based on the 1960 family of RISC processors is introduced. For the second layer three possibilities are considered: serial interface, parallel bus and local area network. The latter is carefully studied and a low cost alternative to the standard deterministic network MAP is introduced. This cell network is based on the CSMA/DCR protocol implemented on the i82596 coprocessor. Two alternatives are discussed for the programming layer: a parallel programming language based on a scene approach and a C extended language used to program elementary tasks in a robot independent way coupled with an intelligent scheduler used to assign these tasks to the robot arms at run time

Robotic Wireless Sensor Networks

In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future