Adaptive signal strength prediction based on radio propagation models for improving multi-robot navigation strategies

Multi-robot systems, i.e. groups of mobile robots which carry out complex tasks cooperatively, are becoming increasingly important in robotics research. For many applications, like exploration or search and rescue missions, multi-robot systems have great advantages over single robot solutions. Besides their ability to fulfill missions faster, multi-robot systems offer improved fault tolerance and the opportunity to combine a large number of relatively cheap robotic systems with complementary capabilities. For the successful deployment of a multi-robot system, reliable wireless communication plays an important role. Especially if an operator is in the loop, the ability to communicate to every robot at any time can be vital. This article presents a technique to predict the expected signal strength of the wireless communication between mobile robots, based on parametric models of radio wave propagation. The predictor allows to take information about the expected future communication quality into account during mission planning and helps to increase the robustness of navigation strategies for multi-robot systems with respect to communication-loss this way. The presented signal strength predictor adjusts itself on-line to different operation environments and robotic systems being used.