Delay-sensitive Wireless Relaying in Multi-Robot Indoor Networks

With the Industry 4.0 revolution, multi-robot systems (MRS) are used significantly in mission critical applications to monitor remote areas, to supervise factory environments, to efficiently manage the supply chain in large warehouses. MRS not only improves quality of on-site governance, but also reduces human resources considerably. Although these robots are self-sufficient and autonomous agents, they require a continuous communication framework to share data and control information with each other or to a central controller. In such a large indoor multi-robotic deployments, network constraints such as last-mile wireless issues, environmental constraints such as physical obstacles and blockages, and operational constraints such as restricted wireless coverage, mobility, interference, etc. create significant impact on consistent operations of such indoor multi-robot networks. In such dynamic deployments, robots are assigned with tasks such as surveillance of an area, collection of images, videos, etc. and send to a central server for post processing. Collected data are fully or partially delay sensitive and may need to be relayed to the central server within specified time delay. However, at times either due to wireless connectivity loss, battery drainage, or ongoing process, robots are not able to send collected data to the server in time. In this paper, we propose a robotic communication model where relay robots are used to provide temporary last-mile coverage to neighbors and opportunistically relay data from peer robots to the server We implement our models in Robotic Operating System (ROS) which is widely embraced as one of the most popular frameworks for robotics' research and industrial robotics applications.