Technical Reports (CIS)

Document Type

Technical Report

Subject Area


Date of this Version

June 1988


University of Pennsylvania Department of Computer and Information Science Technical Report No. MS-CIS-88-41.


The main idea in this paper is that one cannot discern the part-whole relationship of three-dimensional objects in a passive mode without a great deal of a priori information. Perceptual activity is exploratory, probing and searching. Physical scene segmentation is the first step in active perception. The task of perception is greatly simplified if one has to deal with only one object at a time. This work adapts the non-deterministic Turing machine model and develops strategies to control the interaction between sensors and actions for physical segmentation. Scene segmentation is formulated in graph theoretic terms as a graph generation/decomposition problem. The isomorphism between manipulation actions and graph decomposition operations is defined. The non-contact sensors generate the directed graphs representing the spatial relations among surface regions. The manipulator decomposes these graphs under contact sensor supervision. Assuming a finite number of sensors and actions and a goal state, that is reachable and measurable with the available sensors, the control strategies converge. This was experimentally verified in a real, noisy, and dynamic environment.



Date Posted: 18 September 2007