Efficient Exploration Algorithms for Rough Terrain Modeling Using Triangular Mesh Maps

The objective of this paper is to exploit the potential of considering the information gain in greedy mapping strategies based on a triangular mesh map for automatic modeling of a large rough outdoor environment. An energy cost function is used to represent the travel cost and two methods to estimate possible new terrain in one spot using a 3D image sensor are described. For the first method, assuming a partly known environment, the information gain is estimated by applying the ray tracing algorithm to the known part of the environment. For the second method, the new information gain is calculated using polygon clipping in an unknown environment. Simulation results in a typical rough agricultural field showed that the exploration strategy, which was incorporated with energy consumption and the information gain estimation with a ray tracing algorithm using a coarse map, had an advantage over other polices in terms of energy consumption and the path length.