加工大型工件时精确定位方法的研究

针对大型工件加工时由于难找正引起的定位误差，采用最小二乘法，在三维空间中将实测数据点与CAD模糊理论数据点进行拟合，使其满足每个测量点到标准曲面的距离的平方和达到最小，从而计算出曲面在空间的真实位置，利用该方法可以有效的消除大型工件在加工时的定位误差，该方法已经在某磁悬浮列车轨道梁实际加工中得到应用，并取得了很好的效果。

Precision-positioning methods of machining good-sized workpiece

Aim at the location error which aroused by placing good-sized workpiece, we adopt method of minimum squares to fit measure data to with standard data in three-dimensional space,the principle is to make it satisfy the quadratic sum of distance from each measuring point to standard cuverd surface is the minimum. By this means, we can figure out the real place of surface in the space, therefore eliminating the location error. The software is used in machining Shanghai Maglev train railway girder and acquire better effect.