关键词: 逆向工程, 裁剪曲面重建, 孔洞识别, B样条曲面拟合

Abstract:

An approach was proposed to reconstruct trimmed B-spline surface with irregular boundaries. A base plane was firstly rebuilt to parameterize the data points, and the over-determinant equations were derived taking the control points of B-spline surface as variables. A hole detection algorithm based on valid point identification was proposed to mark holes with no or less data points, and then the CNSP(control network shape preservation) constraints were selectively imposed on control points relevant to holes to guarantee the existence of equations’ least square solution. Finally, an error-controllable algorithm was utilized to reconstruct B-spline surface covering the data points, and then irregular boundaries of trimmed surface could be rebuilt via boundary curves extraction or surface intersection. The proposed approach accordant with design intent is characterized by good shape consistence around holes and high precision of resulted surfaces.

Key words: reverse engineering, trimmed surface reconstruction, hole detection, B-spline surface fitting