A Breadcrumb System for Assisting Outdoor Autonomous Robots with Path Identification and Localization

Many outdoor autonomous robotic applications rely on Global Navigation Satellite Systems (GNSS), or more specifically Global Position Systems (GPS), to localize the robot. However, these systems typically have difficulty in providing accurate measurements under one meter. Hence, additional sensors are fused with GNSS measurements to increase the accuracy of localization. These devices can include, laser range-finders, vision cameras, and wireless beacons. Wireless beacons require additional setup time but are an attractive option for environments where a path may need to be determined and traversed quickly by an autonomous robot. We present a system of wireless beacons dubbed Breadcrumb. The system is designed to be deployed in outdoor environments and provide localization information to autonomous robots in the form of: Breadcrumb GPS locations, wireless ranging, and path planning data. In addition, we detail a algorithm which allows us to reduce the number of GPS modules required by the Breadcrumb network such that only every other Breadcrumb requires a module, while still maintaining the GPS location of each Breadcrumb. This algorithm could also be used in the case of a GPS module failure or spotty connection in networks where every device is equipped with a GPS.