基准平面 meaning in English

base plane
datum level
datum plane
reference plane

First the sketch / datum plane is fitted by least - square distance , then the extruded direction or axis with the flank points of the cloud is extracted in quadratic paogramming arithmetic , and certain points projected to gain 2d sketched datas . feature points are defined to segment the sketch datas , and the sketch profile is generated by fitting separately the line and circle segment
使用最小二乘方法拟合草图基准平面，采用二次规划方法提取拉伸方向和旋转轴线，然后将数据点投影以获取草图数据，通过栅格划分提取草图边界轮廓数据，再对这些边界数据进行基于特征点的分割，以直线和圆弧段拟合出草图轮廓。