G^1连续的截面数据高精度重构方法研究

Research on High-precision Reconstruction of the G^1 Continuous Cross Section Data

针对逆向工程中分段点无法精确提取导致边界约束信息不准确,进而造成截面特征重构结果不理想的问题,提出一种高精度截面数据重构方法。根据截面数据的离散曲率信息初步提取分段点,确定理想分段点所在区域,并以区域端点为界将截面数据分割成具有单一特征的数据段;优先重构直线,再重构自由特征:耦合边界约束模型和自由特征自身的重构模型,建立优化模型,采用拉格朗日乘子法求解。在自由特征的重构过程中,建立特征间连接点的精确提取模型,利用黄金分割法动态搜索最优连接点。实例分析表明,由于特征间连接点的高精度识别,使得重构结果能很好地还原产品模型的初始设计意图,提高了重构三维CAD模型的精度和质量。

A high-precision method is proposed to solve the non-ideal cross section feature reconstruction, because the boundary constraint is imprecise, which is caused by the inaccurate segment point in reverse engineering. According to the discrete curvature of the cross section data information, extract segment points preliminary, determine the ideal region of segment points, and divide sectional data into single feature data segment by a regional endpoint. Reconstruct the line first, and then reconstruct free features. Construct optimization model based on boundary constraint model and free feature reconstruction model, use the Lagrange multiplier method to solve this optimization model. In the process of free feature reconstruction, extraction model of precise connection points between features is set up, using the golden section method dynamic to search the optimal point. Examples show that the reconstruction result can restore the original design intent of the product model, and improve the reconstruction accuracy and quality of three dimensional CAD model.