RationalDMIS 7.1-平面与两偏置圆找正（原点不在偏置圆上）_拟合
如图所示，该零件的特点是两找正孔的连线与坐标轴线不平行，且为间接原点设置。显然，按常规方法很难找正。

考虑到该类产品在实际测量中并不少见，所以，我们根据图样设计要求，选择了既方便操作又便于推广的最佳拟合坐标系的方法，应用效果非常满意。

*具体操作步骤如下：

1.测平面，找正零件坐标系的第一轴；
2.测圆1和圆2；按图样对圆1和圆2进行（2D）理论坐标值的修改；
3.选圆1、圆2平移和旋转完成最佳拟合坐标系的创建过程。

RationalDMIS 7.1-平面与两偏置圆找正（原点不在偏置圆上）_2d_02
RationalDMIS 7.1-平面与两偏置圆找正（原点不在偏置圆上）_2d_03

$$/*  Header
DMISMN/'Created by [爱科腾瑞科技(北京)有限公司-091520-DEMO-11023(力合)] on 星期五, 八月 07, 2020', 4.0
UNITS/MM, ANGDEC, MMPS
WKPLAN/XYPLAN
PRCOMP/ON
TECOMP/ON
FLY/1.0000
MODE/MAN
SNSET/APPRCH, 2.0000
SNSET/RETRCT, 2.0000
SNSET/DEPTH, 0.0000
SNSET/SEARCH, 10.0000
SNSET/CLRSRF, 15.0000
RECALL/D(MCS)
SNSLCT/S(D2L20)
GEOALG/BF, LSTSQR
GEOALG/ANGLB, DEFALT
GEOALG/CIRCLE, LSTSQR
GEOALG/ARC, LSTSQR
GEOALG/PLANE, LSTSQR
$$
$$
$$*/
MODE/MAN
F(PLN1)=FEAT/PLANE,CART,8.2750,-11.5012,0.0000,0.0000,0.0000,1.0000
$$ Measurement points are created through nominal points
MEAS/PLANE, F(PLN1), 4
  PTMEAS/CART, -45.0507,  20.7017, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART, -42.1216, -43.6316, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART,  60.4011, -45.5267, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART,  59.8712,  22.4520, 0.0000, 0.0000, 0.0000, 1.0000
ENDMES
D(CRD1) = DATSET/FA(PLN1), ZDIR
D(CRD1) = TRANS/ZORIG, FA(PLN1)
F(CIR1)=FEAT/CIRCLE,INNER,CART,-30.0000,14.0000,-3.7065,0.0000,0.0000,1.0000, 10.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR1), 4
  PTMEAS/CART, -32.0702, 18.5513, -3.1484,  0.4140, -0.9103,  0.0000
  PTMEAS/CART, -25.0354, 14.5938, -4.6197, -0.9929, -0.1188, -0.0000
  PTMEAS/CART, -27.6229,  9.6012, -3.3497, -0.4754,  0.8798,  0.0000
  PTMEAS/CART, -33.7601, 10.7044, -3.7084,  0.7520,  0.6591,  0.0000
ENDMES
F(CIR2)=FEAT/CIRCLE,INNER,CART,50.0000,-34.0000,-3.9597,0.0000,0.0000,1.0000, 10.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(CIR2), 4
  PTMEAS/CART, 49.6933, -29.0094, -4.7922,  0.0613, -0.9981,  0.0000
  PTMEAS/CART, 55.0000, -33.9866, -4.3282, -1.0000, -0.0027, -0.0000
  PTMEAS/CART, 51.1884, -38.8567, -3.0298, -0.2377,  0.9713,  0.0000
  PTMEAS/CART, 46.7478, -37.7978, -3.6887,  0.6504,  0.7596,  0.0000
ENDMES
F(CIR1)=FEAT/CIRCLE,INNER,CART,-30.0000,14.0000,-3.7065,0.0000,0.0000,1.0000, 10.0000
F(CIR2)=FEAT/CIRCLE,INNER,CART,50.0000,-34.0000,-3.9597,0.0000,0.0000,1.0000, 10.0000
DMESW/COMAND,'D(CRD2) = LOCATE/XYDIR, ZAXIS, $
  FA(CIR1), XYZAXI, $
  FA(CIR2), XYZAXI'

RationalDMIS 7.1-平面与两偏置圆找正（原点不在偏置圆上）_坐标轴_04