Free Space Computation Using Stochastic Occupancy Grids and Dynamic Programming

Abstract. The computation of free space available in an environment is an essential task for many intelligent automotive and robotic applications. This paper proposes a new approach, which builds a stochastic occupancy grid to address the free space problem as a dynamic programming task. Stereo measurements are integrated over time reducing disparity uncertainty. These integrated measurements are entered into an occupancy grid, taking into account the noise properties of the measurements. In order to cope with real-time requirements of the application, three occupancy grid types are proposed. Their applicabilities and implementations are also discussed. Experimental results with real stereo sequences show the robustness and accuracy of the method. The current implementation of the method runs on off-the-shelf hardware at 20 Hz.