New accessibility computation for a polyhedral model and a nurbs model in tool-based manufacturing | |
| Author | Kittichai Suthunyatanakit |
| Call Number | AIT Diss. no.ISE-09-06 |
| Subject(s) | Computer-aided design Computer-aided engineering |
| Note | A submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering in Design and Manufacturing, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. ISE-09-06 |
| Abstract | In design and manufacturing, accessibility information plays a significant role because it is used to decide whether a designed product is manufacturable or not. In addition, it is adopted to find the optimal solutions in manufacturing (e.g. minimal setup orientations in machining); i.e. this responds directly to design and manufacturing time, and operational cost. In the research area, accessibility computation has been developed in the aspects of a geometric model (i.e. either a polyhedral model or a surface model), an accessibility solution (i.e. an accessibility cone as an exact solution, and a binary spherical map as an approximate solution), and computational performance. Due to these aspects, the accessi-bility is studied in this dissertation in order to: •Compute the accessibility information from either a polyhedral model or a surface model •Find the accessibility information as the exact solution •Shorten the computational time •Enhance the scope and capability of a NURBS model Hence, this dissertation proposes two approaches: polyhedral-based accessibility compu-tation and NURBS-based accessibility computation. First, a new algorithm for computing exact global accessibility cones from a polyhedral model is proposed in three main steps: concave region extraction, inaccessibility analysis and global accessibility determination. It significantly improves the computational efficiency by the concave region extraction, the 2D convex determination instead of 3D in the inaccessibility analysis, and the near-exact global accessibility method. In this approach, geometric examples are demonstrated and a comparison of the computational complexity with existing algorithm is provided. Second,a new approach is to compute accessibility information (i.e. a local accessibility cone, an inaccessibility cone and a global accessibility cone) from a NURBS model. It has four main steps: preprocessing, local accessibility cone determination, inaccessibility cone determination, and global accessibility cone determination. This approach is developed by extending the polyhedral-based accessibility computation (i.e. the first approach). In addition to global point accessibility, global patch accessibility is newly defined. In the approach, an investigation of computational complexity is provided. |
| Year | 2009 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. ISE-09-06 |
| Type | Dissertation |
| School | School of Engineering and Technology (SET) |
| Department | Department of Industrial Systems Engineering (DISE) |
| Academic Program/FoS | Industrial Systems Engineering (ISE) |
| Chairperson(s) | Bohez, Erik L.J.; |
| Examination Committee(s) | Kittinan Unnanon ;Guha, Sumanta; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2009 |