Occlusion-free path planning with a probabilistic roadmap

We present a novel algorithm for path planning that avoids occlusions of a visual target for an ldquoeye-in-handrdquo sensor on an articulated robot arm. We compute paths using a probabilistic roadmap to avoid collisions between the robot and obstacles, while penalizing trajectories that do not maintain line-of-sight. The system determines the space from which line-of-sight is unimpeded to the target (the visible region). We assign penalties to trajectories within the roadmap proportional to the distance the camera travels while outside the visible region. Using Dijkstrapsilas algorithm, we compute paths of minimal occlusion (maximal visibility) through the roadmap. In our experiments, we compare a shortest-distance path to the minimal-occlusion path and discuss the impact of the improved visibility.