RationalDMIS 2020两偏置圆建立零件坐标系（特殊的零件找正技巧）

通过两个圆的坐标偏置值进行坐标轴的找正是箱体类工件常见的问题。

具体操作方法如下：

1、测平面1，找正零件坐标系的第一轴Z正，Z轴平移到平面1上；

MODE/MAN
F(平面1)=FEAT/PLANE,CART,28.8965,19.1866,0.0000,0.0000,0.0000,1.0000
$$ Measurement points are created through nominal points
MEAS/PLANE, F(平面1), 4
  PTMEAS/CART, -22.6759,  46.2774, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART, -23.1099, -10.4254, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART,  79.2456, -11.6270, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART,  82.1262,  52.5212, 0.0000, 0.0000, 0.0000, 1.0000
ENDMES
D(CRD1) = DATSET/FA(平面1), ZDIR
D(CRD1) = TRANS/ZORIG, FA(平面1)

2、测圆1，并平移【X、Y】原点至圆1中心；

F(圆1)=FEAT/CIRCLE,INNER,CART,0.0000,0.0000,-3.0000,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(圆1), 4
  PTMEAS/CART, -0.9932,  9.9506, -3.0000,  0.0993, -0.9951,  0.0000
  PTMEAS/CART,  9.9392,  1.1008, -3.0000, -0.9939, -0.1101, -0.0000
  PTMEAS/CART, -0.9158, -9.9580, -3.0000,  0.0916,  0.9958,  0.0000
  PTMEAS/CART, -9.7076, -2.4003, -3.0000,  0.9708,  0.2400,  0.0000
ENDMES
D(CRD2) = TRANS/XORIG, FA(圆1), YORIG, FA(圆1)

3、测圆2，然后打开坐标编辑框，对圆2【X、Y】理论坐标值按图样进行修改；

F(圆2)=FEAT/CIRCLE,INNER,CART,60.0000,40.0000,-3.0000,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(圆2), 4
  PTMEAS/CART, 58.8883, 49.9380, -3.0000,  0.1112, -0.9938,  0.0000
  PTMEAS/CART, 69.5537, 42.9542, -3.0000, -0.9554, -0.2954, -0.0000
  PTMEAS/CART, 60.3078, 30.0047, -3.0000, -0.0308,  0.9995,  0.0000
  PTMEAS/CART, 50.9093, 35.8335, -3.0000,  0.9091,  0.4167,  0.0000
ENDMES
F(圆2)=FEAT/CIRCLE,INNER,CART,60.0000,40.0000,-3.0000,0.0000,0.0000,1.0000, 20.0000

4、选圆1、圆2进行坐标系多点拟合（最佳拟合）（给定条件选仅Z轴旋转），即完成坐标系的找正过程。

$$/*  Header
DMISMN/'Created by [爱科腾瑞科技(北京)有限公司-091521-DEMO-11022(华清)] on 星期二, 四月 06, 2021', 4.0
UNITS/MM, ANGDEC, MMPS
WKPLAN/XYPLAN
PRCOMP/ON
TECOMP/ON
FLY/1.0000
MODE/MAN
SNSET/APPRCH, 2.0000
SNSET/RETRCT, 2.0000
SNSET/DEPTH, 0.0000
SNSET/SEARCH, 10.0000
SNSET/CLRSRF, 20.0000
RECALL/D(MCS)
SNSLCT/S(40-D2)
GEOALG/BF, LSTSQR
GEOALG/ANGLB, DEFALT
GEOALG/CIRCLE, LSTSQR
GEOALG/ARC, LSTSQR
GEOALG/PLANE, LSTSQR
$$
$$
$$*/
MODE/MAN
F(平面1)=FEAT/PLANE,CART,28.8965,19.1866,0.0000,0.0000,0.0000,1.0000
$$ Measurement points are created through nominal points
MEAS/PLANE, F(平面1), 4
  PTMEAS/CART, -22.6759,  46.2774, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART, -23.1099, -10.4254, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART,  79.2456, -11.6270, 0.0000, 0.0000, 0.0000, 1.0000
  PTMEAS/CART,  82.1262,  52.5212, 0.0000, 0.0000, 0.0000, 1.0000
ENDMES
D(CRD1) = DATSET/FA(平面1), ZDIR
D(CRD1) = TRANS/ZORIG, FA(平面1)
F(圆1)=FEAT/CIRCLE,INNER,CART,0.0000,0.0000,-3.0000,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(圆1), 4
  PTMEAS/CART, -0.9932,  9.9506, -3.0000,  0.0993, -0.9951,  0.0000
  PTMEAS/CART,  9.9392,  1.1008, -3.0000, -0.9939, -0.1101, -0.0000
  PTMEAS/CART, -0.9158, -9.9580, -3.0000,  0.0916,  0.9958,  0.0000
  PTMEAS/CART, -9.7076, -2.4003, -3.0000,  0.9708,  0.2400,  0.0000
ENDMES
D(CRD2) = TRANS/XORIG, FA(圆1), YORIG, FA(圆1)
F(圆2)=FEAT/CIRCLE,INNER,CART,60.0000,40.0000,-3.0000,0.0000,0.0000,1.0000, 20.0000
$$ Measurement points are created through nominal points
MEAS/CIRCLE, F(圆2), 4
  PTMEAS/CART, 58.8883, 49.9380, -3.0000,  0.1112, -0.9938,  0.0000
  PTMEAS/CART, 69.5537, 42.9542, -3.0000, -0.9554, -0.2954, -0.0000
  PTMEAS/CART, 60.3078, 30.0047, -3.0000, -0.0308,  0.9995,  0.0000
  PTMEAS/CART, 50.9093, 35.8335, -3.0000,  0.9091,  0.4167,  0.0000
ENDMES
F(圆2)=FEAT/CIRCLE,INNER,CART,60.0000,40.0000,-3.0000,0.0000,0.0000,1.0000, 20.0000
DMESW/COMAND,'D(CRD3) = LOCATE/NOTRAN, ZAXIS, $
  FA(圆1), XYZAXI, $
  FA(圆2), XYZAXI'