The first aim of the project, (“Optical RE” in the Fig. 3) is to optimize the RE process as far as the time of execution, by creating a 3D model for the description of the object under test by using the optical digitization. This objective has been performed in the following steps:
- development of a reliable and easy to use optical digitizer, able to generate 3D point clouds that describe various parts of the object, each from a specific viewpoint; the measurement system, should be easily movable in space, in order to be able to “observe” the target object from different perspectives, and to create a set of point clouds that completely describe the object itself;
- development of procedures for the registration of the point clouds;
- development of the procedures for the creation, starting from the registered views, of 3D models of the shapes;
- metrological validation of the models by means of the CMM.
The second purpose of the project (“Optical/Contact RE” in Fig. 3) is to optimize the RE process from the viewpoint of the accuracy of the representation of the object, without increasing the process time. The approach is close to that one represented in Fig. 2; however, the initial representation of the CAD model has to be obtained starting from the above mentioned 3D models.
Metrological validation of Point Clouds
The third purpose of the project (“Metrological validation of point clouds” in the Fig. 3) is closely related to the activity aimed at metrologically validating, by means of the CMM, the point clouds generated by the optical digitizer.
Validation for RP
The final goal of the project (“Validation for RP” in Fig. 3) is the verification of the suitability of the 3D models for the Rapid Prototyping process.
The activity carried out by our Laboratory resulted in two research products. The former is the optical digitizer OPL-3D. The design and the development of the instrument have been completely performed by the Laboratory. The metrological characterization has been performed in collaboration with the Laboratory located in Padova.
The latter is a suite of software tools for the alignement of the point clouds in the multi-view acquisition process. These tools perform, in a semi-automatic way, the estimate of the rototranslation matrixes between pairs of point clouds. A further improvement is performed by the research Laboratory located in Milan, basically aimed at achieving a completely automatic process. Below you can find more details about the procedures.