A frontier-void-based approach for autonomous exploration in 3D.

We consider the problem of an autonomous robot searching for objects in unknown 3D space. Similar to the well-known frontier-based exploration in 2D, the problem is to determine a minimal sequence of sensor viewpoints until the entire search space has been explored. We introduce a novel approach that combines the two concepts of voids, which are unexplored volumes in 3D, and frontiers, which are regions on the boundary between voids and explored space. Our approach has been evaluated on a mobile platform using a 5-DOF manipulator searching for victims in a simulated urban search and rescue setup. The results indicate the real-world capability and search efficiency of the proposed method.