A method based on point cloud sectioning to evaluate different sources of error on the shape of a manufactured object

Abstract

ABSTRACTThis paper presents a method to evaluate the accuracy of a manufactured object with respect to its original CAD model. Different errors caused by the manufacturing process are assumed to come from global axis deformation and transverse sections rotation of the object with respect to its ideal CAD. Object and CAD shapes are given in form of point clouds, the former derived from a laser-scanning measurement, the latter from sampling the ideal surface by a dense and uniform point grid. Point clouds are sectioned in a finite number of thin blocks. This method has been applied to the analysis of a helical Darrieus blade prototype, parametrically designed and modelled with McNeel Rhinoceros and Grasshopper software, manufactured with a three-axes Computer Numerical Control machine. This procedure is able to check the conformity of the manufactured airfoil to the theoretical one and to establish the efficiency of the final prototype of the blade turbine.