Coordinated Search in Cluttered Environments Using Range from Multiple Robots

In this paper, we describe real-time methods for incorporating non-line-of-sight range measurements into a framework for finding a non-adversarial target in cluttered environments using multiple robotic searchers. We extend previous coordinated search strategies to utilize information from noisy non-line-of-sight range measurements. Sensors using ultra-wideband radio are becoming available that provide range measurements to targets even when they are occluded. We present two Bayesian methods for updating the expected location of a mobile target and integrating these updates into planning. We present simulated results in a complex museum environment as well as on mobile robots. Our results show the success of our algorithms at utilizing information from measurements in a coordinated search framework.