Exploring environments to generate 3D maps is a core component of any autonomous robot expected to operate in search and rescue or security related missions. Considering that information about surface voxels in a 3D grid map is sufficient for many tasks, following a mapping mission, such as motion planning for searching or rescue, this paper presents an exploration strategy guided by surface frontiers rather than free-space frontiers to actively map the object surfaces in the environment. Surface frontiers in a 3D grid map are surface boundary voxels neighboring unmapped space. Detecting surface frontiers from a 3D occupancy grid is discussed in detail and a strategy to sample view configurations using the detected surface frontiers for exploration is provided. Exploration experiments conducted in both simulated and real indoor environments validate that surface frontiers are a valid and an efficient alternative for freespace frontiers for autonomous 3D exploration.
['P. G. C. N. Senarathne', 'Danwei Wang']
Towards autonomous 3D exploration using surface frontiers