This paper is centered around landmark detection, tracking and matching for visual SLAM (Simultaneous Localization And Mapping) using a monocular vision system with active gaze control. We present a system specialized in creating and maintaining a sparse set of landmarks based on a biologically motivated feature selection strategy. A visual attention system detects salient features which are highly discriminative, ideal candidates for visual landmarks which are easy to redetect. Features are tracked over several frames to determine stable landmarks and to estimate their 3D position in the environment. Matching of current landmarks to database entries enables loop closing. Active gaze control allows us to overcome some of the limitations of using a monocular vision system with a relatively small field of view. It supports (i) the tracking of landmarks which enable a better pose estimation, (ii) the exploration of regions without landmarks to obtain a better distribution of landmarks in the environment, and (iii) the active redetection of landmarks to enable loop closing in situations in which a fixed camera fails to close the loop. Several real-world experiments show that accurate pose estimation is obtained with the presented system and that active camera control outperforms the passive approach.

Abstract. Due to stringing time constraints, saliency models are becoming popular tools for building situated robotic systems requiring, for instance, object recognition and vision-based localisation capabilities. This paper contributes to this endeavour by applying saliency into two new tasks: modulation of stereobased obstacle detection and ground-plane estimation, both to operate on-board off-road vehicles. To achieve this, a new biologically inspired saliency model, along with a set of adaptations to the task-specific algorithms, are proposed. Experimental results show a reduction in computational cost and an increase in both robustness and accuracy when saliency modulation is used. 1