RPS系统就是规定一些从开发到制造、检测直至批量装车各环节所有涉及到的人员共同遵循的定位点及其公差要求。在确定这些定位点时必须遵循RPS系统的规则。其作用：
1、避免了由于基准点的变换造成零件尺寸公差加大
2、避免了模板的作用
3、RPS点是模具、工装、检具的定位点
在一些产品的设计图中，就按六点定位的原则明确定义了一组基准位置，操作者在进行零件找正时，就必须按照这些位置去找正，并把它们的坐标位置设置为图纸上指定的数值。这种方法就是RPS找正方法，它明确规定了找正的位置和坐标数据，避免了因为选择不同的基准导致的制造和测量误差。
功能：RPS找正建立零件坐标系主要应用在PCS的原点不在工件本身、或无法找到相应的基准元素（如面、孔、线等）来确定轴向或原点，多为曲面薄臂、板金类零件（汽车、飞机的配件，这类零件的坐标系多在车身或机身上）。
RPS找正原理:用点性几何元素(如:点、圆、椭圆、球、方槽、圆槽）进行找正。
1. 第一组特征将拟合平面特征，必须使用三个特征建立当前工作平面法线轴的方向，空间旋转确定第一轴和坐标原点。
2. 第二组特征将拟合直线特征，必须使用两个特征从而将工作平面的定义轴旋转到特征点上，平面旋转确定第二轴，确定第三轴的坐标原点。
3. 最后一组特征用于确定第二轴的坐标原点。
4. 尽可能的保证这三组特征之间有近似垂直关系。
MODE/PROG,MAN
GOTO/46.4280, 74.8627, 638.7968
(ITR_START)
F(DC-1)=FEAT/POINT,CART,19.9704,27.3795,697.7035,-0.4847,0.8744,-0.0206
MEAS/POINT, F(DC-1), 1
PTMEAS/CART, 19.9704,27.3795,697.7035,-0.4847,0.8744,-0.0206
ENDMES
F(DC-2)=FEAT/POINT,CART,-1.0205,15.6860,695.2357,-0.4847,0.8744,-0.0206
MEAS/POINT, F(DC-2), 1
PTMEAS/CART, -1.0205,15.6860,695.2357,-0.4847,0.8744,-0.0206
ENDMES
F(DC-3)=FEAT/POINT,CART,8.9198,19.8987,640.1704,-0.4847,0.8744,-0.0206
MEAS/POINT, F(DC-3), 1
PTMEAS/CART, 8.9198,19.8987,640.1704,-0.4847,0.8744,-0.0206
ENDMES
GOTO/23.2923, 70.1593, 640.0797
GOTO/70.1338, 30.8778, 696.3955
F(DC-4)=FEAT/POINT,CART,25.0000,23.8764,696.6221,1.0000,0.0000,-0.0000
MEAS/POINT, F(DC-4), 1
PTMEAS/CART, 25.0000,23.8764,696.6221,1.0000,0.0000,-0.0000
ENDMES
F(DC-5)=FEAT/POINT,CART,25.0000,24.0451,641.2571,1.0000,0.0000,-0.0000
MEAS/POINT, F(DC-5), 1
PTMEAS/CART, 25.0000,24.0451,641.2571,1.0000,0.0000,-0.0000
ENDMES
GOTO/42.4814, 31.3370, 641.2418
GOTO/-36.6582, 88.1126, 641.3778
GOTO/-19.3144, 19.5720, 663.6754
F(DC-6)=FEAT/POINT,CART,-22.6787,-0.3463,649.4999,-0.0000,-0.0005,1.0000
MEAS/POINT, F(DC-6), 1
PTMEAS/CART, -22.6787,-0.3463,649.4999,-0.0000,-0.0005,1.0000
ENDMES
F(DC-1)=FEAT/POINT,CART,19.9704,27.3795,697.7035,-0.4847,0.8744,-0.0206
F(DC-2)=FEAT/POINT,CART,-1.0205,15.6860,695.2357,-0.4847,0.8744,-0.0206
F(DC-3)=FEAT/POINT,CART,8.9198,19.8987,640.1704,-0.4847,0.8744,-0.0206
F(DC-4)=FEAT/POINT,CART,25.0000,23.8764,696.6221,1.0000,0.0000,-0.0000
F(DC-5)=FEAT/POINT,CART,25.0000,24.0451,641.2571,1.0000,0.0000,-0.0000
F(DC-6)=FEAT/POINT,CART,-22.6787,-0.3463,649.4999,-0.0000,-0.0005,1.0000
DMESW/COMAND,'D(CRD2) = LOCATE/XYZDIR, XYZAXI, $
FA(DC-1), YAXIS, $
FA(DC-2), YAXIS, $
FA(DC-3), YAXIS, $
FA(DC-4), XAXIS, $
FA(DC-5), XAXIS, $
FA(DC-6), ZAXIS'
KNPTR1 = ITERAT/(ITR_START), (ITR_FAIL), 0.050000, ABSL, 5,$
FA(DC-1), 0, 1, 0,$
FA(DC-2), 0, 1, 0,$
FA(DC-3), 0, 1, 0,$
FA(DC-4), 1, 0, 0,$
FA(DC-5), 1, 0, 0,$
FA(DC-6), 0, 0, 1
(ITR_FAIL)
$$ Set.CAD2PCS.CADM_1
