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Ko, Heedong 2011-05-07T12:55:32Z 2011-05-07T12:55:32Z 10000-01-01 1989 An assembly structure is a physical as well as a conceptual structure. Physically, an assembly structure is composed of individual components and their relationships. Conceptually, an assembly structure is hierarchically organized into subassemblies. The focus is to generate an assembly sequence from a physical specification of the assembly structure. A component is modeled iconographically as well as by its geometric features: outer normal of a face, center axis of a hole, and more. Two components mate when their features are connected by a set of fixed geometric and kinematic relationships, called mating conditions. These connections are specified by an assembly designer. An assembly planner generates a sequence of mating operations inferred from the specified mating conditions. Mating conditions specify the assembly structure to be constructed: a goal state for the planner. The goal state is hierarchically structured into subassemblies, forming an assembly hierarchy. Using the assembly hierarchy as an abstraction hierarchy, the planner reduces the planning task because a subassembly should be assembled before its parent assembly structure. Two assembly planning approaches are developed. One is based on detecting spatial interferences between sibling subassemblies. The other is based on planning with prior experiences. The latter approach monitors the execution of an assembly sequence, generated from the previous experience, whether there exist any collision free path when executing an assembly operation among the already assembled components, obstructing a collision free path. When failure is detected, the planning experience is modified so that the planner avoids repeating the same mistake. Made available in DSpace on 2011-05-07T12:55:32Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 8924862.pdf: 6248620 bytes, checksum: f0864bd6dcee563fba5a1d73ed5d1973 (MD5) Previous issue date: 1989 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:47:50Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:21:37-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI8924862 (UMI)AAI8924862 http://hdl.handle.net/2142/21005 eng Copyright 1989 Ko, Heedong Artificial Intelligence Computer Science Empirical assembly planning: A learning approach text Computer Science Computer Science University of Illinois at Urbana-Champaign Dissertation Ph.D.