RationalDMIS 2020 迭代对齐建坐标系

在使用三坐标检测产品时我们常常会用到坐标系，而我们常见的坐标系是笛卡尔坐标系，它满足以下几个特点：

1、坐标系的三个轴向两两垂直；

2、坐标系的指向满足右手定则。

在建立零件坐标系的时常用的手法就是3-2-1法，将产品的零件坐标系建立在产品的基准之上。然而对于很多汽车零部件而言零件在设计时考虑到装配会按照统一的汽车坐标系设计。这时3-2-1建坐标的方法就无法满足我们的测量需求了，今天我们介绍的迭代对齐就可以有效解决这个问题

1.在模型上选取参考点

$$/*  Header
DMISMN/'Created by [爱科腾瑞科技(北京)有限公司-091521-DEMO-11022(华清)] on 星期四, 四月 08, 2021', 4.0
UNITS/MM, ANGDEC, MMPS
WKPLAN/XYPLAN
PRCOMP/ON
TECOMP/ON
FLY/1.0000
MODE/MAN
SNSET/APPRCH, 2.0000
SNSET/RETRCT, 2.0000
SNSET/DEPTH, 0.0000
SNSET/SEARCH, 10.0000
SNSET/CLRSRF, 20.0000
RECALL/D(MCS)
SNSLCT/S(40-D2)
GEOALG/BF, LSTSQR
GEOALG/ANGLB, DEFALT
GEOALG/CIRCLE, LSTSQR
GEOALG/ARC, LSTSQR
GEOALG/PLANE, LSTSQR
$$
$$
$$*/
MODE/MAN
F(PT1)=FEAT/POINT,CART,8.6562,251.7081,0.0000,0.0000,0.0000,1.0000
F(PT2)=FEAT/POINT,CART,13.0992,51.0568,0.0000,0.0000,0.0000,1.0000
F(PT3)=FEAT/POINT,CART,136.5383,32.9512,0.0000,0.0000,0.0000,1.0000
F(PT4)=FEAT/POINT,CART,186.6490,275.8631,0.0000,0.0000,0.0000,1.0000
F(PT5)=FEAT/POINT,CART,38.7520,0.0000,-4.7355,0.0000,-1.0000,0.0000
F(PT6)=FEAT/POINT,CART,149.2353,0.0000,-5.6508,0.0000,-1.0000,0.0000
F(PT7)=FEAT/POINT,CART,0.0000,43.8960,-3.4677,-1.0000,0.0000,0.0000
F(PT8)=FEAT/POINT,CART,0.0000,132.7173,-4.3188,-1.0000,0.0000,0.0000
F(PT9)=FEAT/POINT,CART,0.0000,266.2136,-6.7227,-1.0000,0.0000,0.0000
MEAS/POINT, F(PT1), 1PTMEAS/CART, 8.6562,251.7081,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT2), 1PTMEAS/CART, 13.0992,51.0568,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT3), 1PTMEAS/CART, 136.5383,32.9512,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT4), 1PTMEAS/CART, 186.6490,275.8631,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT5), 1PTMEAS/CART, 38.7520,0.0000,-4.7355,0.0000,-1.0000,0.0000
ENDMES
MEAS/POINT, F(PT6), 1PTMEAS/CART, 149.2353,0.0000,-5.6508,0.0000,-1.0000,0.0000
ENDMES
MEAS/POINT, F(PT7), 1PTMEAS/CART, 0.0000,43.8960,-3.4677,-1.0000,0.0000,0.0000
ENDMES
MEAS/POINT, F(PT8), 1PTMEAS/CART, 0.0000,132.7173,-4.3188,-1.0000,0.0000,0.0000
ENDMES
MEAS/POINT, F(PT9), 1PTMEAS/CART, 0.0000,266.2136,-6.7227,-1.0000,0.0000,0.0000
ENDMES

将所选点编写到程序中，运行程序获得点的实测值。

使用迭代对齐建坐标，首先我们需要在产品上选择6个以上的点作为参考，这些点需要分布在产品的各个方向上，最终要能够限制住产品的6个自由度。基准元素也可以使用圆，但最多只能加入2个圆参与迭代对齐。

2.设置迭代关系

将得到实测值的参考特征拖入元素区域，导入的模型作为理论参考拖入CAD模型栏。设置好迭代的次数和变换的目标公差，点击迭代即可完成迭代计算。完成迭代后点击添加激活坐标系，得到我们需要的坐标系。

最大迭代：迭代次数达到设置的数值后
迭代停止。

变换值：当迭代误差小于此值迭代停止。

原始LSE：是拟和前最小均方差之和。

新LSE：是拟和后最小均方差之和。

迭代：软件会自动根据CAD数模和测量点来进行坐标系的迭代运算，并根据用户输入的对齐条件，自动计算出控制CAD对齐的坐标系。

$$/*  Header
DMISMN/'Created by [爱科腾瑞科技(北京)有限公司-091521-DEMO-11022(华清)] on 星期四, 四月 08, 2021', 4.0
UNITS/MM, ANGDEC, MMPS
WKPLAN/XYPLAN
PRCOMP/ON
TECOMP/ON
FLY/1.0000
MODE/MAN
SNSET/APPRCH, 2.0000
SNSET/RETRCT, 2.0000
SNSET/DEPTH, 0.0000
SNSET/SEARCH, 10.0000
SNSET/CLRSRF, 20.0000
RECALL/D(MCS)
SNSLCT/S(40-D2)
GEOALG/BF, LSTSQR
GEOALG/ANGLB, DEFALT
GEOALG/CIRCLE, LSTSQR
GEOALG/ARC, LSTSQR
GEOALG/PLANE, LSTSQR
$$
$$
$$*/
MODE/MAN
F(PT1)=FEAT/POINT,CART,8.6562,251.7081,0.0000,0.0000,0.0000,1.0000
F(PT2)=FEAT/POINT,CART,13.0992,51.0568,0.0000,0.0000,0.0000,1.0000
F(PT3)=FEAT/POINT,CART,136.5383,32.9512,0.0000,0.0000,0.0000,1.0000
F(PT4)=FEAT/POINT,CART,186.6490,275.8631,0.0000,0.0000,0.0000,1.0000
F(PT5)=FEAT/POINT,CART,38.7520,0.0000,-4.7355,0.0000,-1.0000,0.0000
F(PT6)=FEAT/POINT,CART,149.2353,0.0000,-5.6508,0.0000,-1.0000,0.0000
F(PT7)=FEAT/POINT,CART,0.0000,43.8960,-3.4677,-1.0000,0.0000,0.0000
F(PT8)=FEAT/POINT,CART,0.0000,132.7173,-4.3188,-1.0000,0.0000,0.0000
F(PT9)=FEAT/POINT,CART,0.0000,266.2136,-6.7227,-1.0000,0.0000,0.0000
MEAS/POINT, F(PT1), 1PTMEAS/CART, 8.6562,251.7081,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT2), 1PTMEAS/CART, 13.0992,51.0568,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT3), 1PTMEAS/CART, 136.5383,32.9512,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT4), 1PTMEAS/CART, 186.6490,275.8631,0.0000,0.0000,0.0000,1.0000
ENDMES
MEAS/POINT, F(PT5), 1PTMEAS/CART, 38.7520,0.0000,-4.7355,0.0000,-1.0000,0.0000
ENDMES
MEAS/POINT, F(PT6), 1PTMEAS/CART, 149.2353,0.0000,-5.6508,0.0000,-1.0000,0.0000
ENDMES
MEAS/POINT, F(PT7), 1PTMEAS/CART, 0.0000,43.8960,-3.4677,-1.0000,0.0000,0.0000
ENDMES
MEAS/POINT, F(PT8), 1PTMEAS/CART, 0.0000,132.7173,-4.3188,-1.0000,0.0000,0.0000
ENDMES
MEAS/POINT, F(PT9), 1PTMEAS/CART, 0.0000,266.2136,-6.7227,-1.0000,0.0000,0.0000
ENDMES
MA(MATDEF1) = MATDEF/F(CADM_1),FA(PT1),FA(PT2),FA(PT3),FA(PT4),FA(PT5),FA(PT6),FA(PT7),FA(PT8),FA(PT9)
DMESW/COMAND, 'ITERATION/100'
D(CRD1)=LOCATE/MA(MATDEF1)
$$ Set.CAD2PCS.CADM_1
$$ Set.CADViewCenter.CADM_1