3D Metrology and Reverse Engineering for Micro Products

Reverse engineering (RE) is the process of analysing a subject system or product to identify its components and their interrelationships and create representations of the system or product in another form or at a higher level of abstraction. In production engineering, RE is a term used to describe the creation of a digital dataset based on a physical representation, inverting the regular process of going from an idea through CAD/CAM construction to a product. The RE process can be subdivided into three stages: data acquisition, data segmentation and CAD modelling and/or updating. A physical mock up, sample or prototype is first measured using different digitising techniques to acquire the geometric information in the form of point cloud. The point cloud obtained is then used to create a surface CAD model for the object through segmentation and surface fitting. Segmentation is concerned with sorting the points and determining which surface they belong to; this part of the process usually involves considerable user interaction. Surface fitting can be carried out using several approaches such as the application of B-Spline or NURBS equations to fit surfaces and skin the point cloud; a variety of RE software is available to reconstruct the actual shape in a required CAD format.