Three-dimensional Model Of Fan Blade Based On The Coordinate Measuring Reconstruction Technique And NC Machining Simulation

The fan blade as the key components of the mine ventilation,its design is an importantprerequisite to ensure efficient production. Reverse engineering is a high efficiency, low cost,new design patterns. The surface of the fan blade is reconstructed by using the point clouddata measuring, point cloud data pre-processing and reconstruction technologies based onreverse engineering technology.Then the entity model generation and NC machiningsimulation are studied, which laid the foundation for the efficient design and production of thefan blades with a certain theoretical value and practical significance.(1)Through the analysis of characteristics of the blade surface, planning the measurementpath, and using three coordinate measuring machine,the point cloud datas of the fan bladesurface are obtained,this is the basic work for next steps.(2)The measurement data pretreatment is systemly researched, including measuring dataredundancy point removal, data filtering, data streamline, data interpolation, etc.The pointcloud data on each section plane are streamlined through schematic of chord-angle method.(3)This paper aims at the research object that the point cloud data on mine axial flow fanblade section, a method of the given error of least squares of uniform b-spline fitting andsecond sampling streamline point cloud data is putted forward.(4)The methods of non-uniform rational non-even B-spline surface and NURBS surfacereconstructing are studied.Firstly, the fitting method of curve and surface and the mathematicsknowledge of non-even B-spline and NURBS surface are introuduced.Secondly,the sectionpoint cloud data obtained after the pretreatment is carried on two times of sampling to obtainpoints of the direction u curve value.Thirdly,the non-even B-spline base is made use of thenon-even nodal point vector that is made from the method of accumulation the chordlength,which establishes the calculating equation of the control point to reverse calculate thecontrol point.Finally,it takes the direction u control point as the direction v value point toreverse calculate and obtain direction v control point.(5) The point cloud datas on the fitting surface are extracted and imported to theImageware module in UG software for surface generation, and then a solid model is generatedin UG, the last the CNC method of the fan blades is studied, and machine tool production codeis gained.