zePPeLIN: Ceiling camera networks for the distributed path planning of ground robots

We introduce zePPeLIN, a distributed system designed to address the challenges of path planning in large, cluttered, and dynamic environments. The objective is to define the sequence of instructions to move a ground object from an initial to a final configuration in the environment. zePPeLIN is based on a set of wirelessly networked devices, each equipped with a camera, deployed in environment. Cameras are placed at the ceiling. While each camera only covers a limited environment portion, the camera set fully covers the environment through the union of the field of views. By local message exchanging, the cameras cooperatively compute the path for the object, which gets moving instructions from each camera when it enters camera’s field of view. Path planning is performed in a fully distributed way, based on potential diffusion over local Voronoi skeletons. The task is made challenging by intrinsic errors in the overlapping in cameras’ field of views. We study the performance of the system vs. these errors, as well as its scalability for size and density of the camera network. We also propose a few heuristics to improve performance and computational and communication efficiency. We report about extensive simulation experiments and validation using real devices.