An Improved Algorithm for Normal Vector and Curvature Estimation Based on the Triangularly-meshed Surface in CNC Machining
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摘要: 在面向三角网格曲面的数控加工中,网格曲面的曲率估算精度对数控加工刀具路径设计和加工质量具有重要的影响。针对数控加工需求,提出了一种三角网格曲面中网格节点曲率的精确估算方法。该方法引入网格形状因子,综合考虑三角形的形状和面积两个因素对网格节点法矢量的影响,得到了更为精确的法矢量,从而获得网格节点处更为精确的曲率估算值。此方法能够有效提高三角网格节点曲率估算的精确度,提高了三角网格曲面刀具路径设计中的刀位点计算精度和数控加工精度。Abstract: In computer numerical control (CNC) machining for triangular mesh surface, the estimation accuracy of curvature on triangular mesh surface is critical to tool path planning and quality of machining. An accurate algorithm is proposed for evaluating the nodal curvature for triangular mesh surface. Considering the effect of triangular shape on the nodal normal vector, a triangular shape factor is introduced, and it is integrated by weighing the surrounding areas so that the nodal normal vector is determined more precisely. The algorithm can effectively improve the accuracy of nodal curvature estimation for triangular mesh, thus effectively improve the calculation accuracy of cutting location points and machining precision of triangular mesh surface.
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Key words:
- CNC machining /
- curvature estimation /
- nodal normal vector /
- shape factor /
- triangular mesh
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