Physical interaction for segmentation of unknown textured and non-textured rigid objects

We present an approach for autonomous interactive object segmentation by a humanoid robot. The visual segmentation of unknown objects in a complex scene is an important prerequisite for e.g. object learning or grasping, but extremely difficult to achieve through passive observation only. Our approach uses the manipulative capabilities of humanoid robots to induce motion on the object and thus integrates the robots manipulation and sensing capabilities to segment previously unknown objects. We show that this is possible without any human guidance or pre-programmed knowledge, and that the resulting motion allows for reliable and complete segmentation of new objects in an unknown and cluttered environment. We extend our previous work, which was restricted to textured objects, by devising new methods for the generation of object hypotheses and the estimation of their motion after being pushed by the robot. These methods are mainly based on the analysis of motion of color annotated 3D points obtained from stereo vision, and allow the segmentation of textured as well as non-textured rigid objects. In order to evaluate the quality of the obtained segmentations, they are used to train a simple object recognizer. The approach has been implemented and tested on the humanoid robot ARMAR-III, and the experimental results confirm its applicability on a wide variety of objects even in highly cluttered scenes.