Reverse Engineering

Keonys ReverseEng Beetle Big

The need to capture the geometry of an existing physical product arises more and more frequently. This is particularly the case for products that only exist in physical form, or with very old products for which the business does not have archive design data (whether drawing board design or using an old 2D design system) or also in certain manufacturing sectors where validation processes for style forms include production of a physical mock-up.
'Reverse engineering' is a solution involving reconstruction of a 3D model from real measurements of an existing shape. Once reconstructed, the 3D model can be modified and added to an assembly or design, so that a digital mock-up approach can be used throughout.

While 'reverse engineering' was the preserve of large OEMs a few years ago, it can now be found in many areas of activity:

  • Innovation: existing patented technical solutions can be captured for use in CAD, and once digitised, can be analysed, tested and improved.
  • Aesthetics: many product designs make use of designers and start from sculptures or a model (jewellery, toys, perfume, packaging, art pieces). Using a physical model provides a better appreciation of the style and ergonomics of a product. Once the shape has been accepted by the project team, it can be transferred into CAD for completion of the design.
  • Design: life-size mock-ups are used to validate the style. This is how vehicle design starts, and very often the stylist modifies the mock-ups during the design phase and asks for these changes to be reflected in the CAD surface styling.
  • Tooling: when finalising the manufacture of a tooling piece (stamping tool, mould), it is often necessary to modify the tooling piece locally by machining. It is therefore essential to update the CAD models so as to maintain consistency between the tooling piece and its digital definition, for future use and to minimise future adjustments.
  • Quality control: for some parts with complex shapes that are manufactured with equally complex processes (stamping or plastic injection), such as vehicle bonnets or dashboards, it can be difficult to check for deviations using traditional methods. Digitising a part using a scanner provides a scatter of points that can be superimposed on the original CAD definition, so that positional deviations can be displayed.

There are many other application areas in industries such as mechanics, medicine, architecture or even communication.

Digitising is the first step in the 'reverse engineering' process

'Reverse engineering' technologies are increasingly accessible thanks for advances in digitising techniques and CAD solutions. Several hardware technologies can be used to provide capture of physical part shape and dimensions, including two main types of scanner:

  • Contact scanners: used mainly for part verification.
  • Non-contact scanners: used to obtain dense scatters of points. These scanners generally use a laser or white light, and employ a measuring system based on triangulation. Another technology used in the industry is computerised tomography (CT), using X rays. This system analyses the internal and external structure of the part and provides complete internal and external digitising.

The market for these technologies has only begun to develop but should grow rapidly in the years ahead. Digitising the real part results in dense 3D scatters of points, which are used in CAD systems to reconstruct the surfaces.

CATIA reverse engineering solution

Specialised reverse engineering solutions from Dassault Systèmes address each stage of this industrial process.

  • Digitized Shape Editor (DSE):

DSE is a module for capturing and processing dense scatters of points. The module includes all functionality required for quick and easy display, editing and manipulation of dense scatters of points containing up to 10 million points. The digitising information captured can be stored using neutral file formats (*.asc, *.stl) or proprietary file formats (Steinbichler *.ac, Gom *.g3d, KREON *.grk, HYSCAN *.hym). DSE includes powerful functions for processing scatters of points, allowing parasite points to be removed or only selected zones to be retained. All curve creation functions are available for defining the boundaries of future surfaces, while verifying their quality, tangency and curvature conditions.

  • Quick Surface Reconstruction (QSR):
QSR is a product that is unique in the marketplace, allowing semi-automatic or automatic reconstruction of surfaces from scatters of points. QSR's different functions enable:
- automatic boundary curve creation through recognition of the digitised geometry (significant curve changes, sharp edges)
- automatic surface creation through canonical shape recognition (plan, sphere, cylinder, cone) found in the scatter. Certain parameters can be forced in order to refine the results of the processing, such as the radii or the axes.
- automatic surface creation for arbitrary shapes using 'fill ' while respecting the desired criteria with regard to the scatter of points and the tangency and curvature conditions specified. There is no limit to the number of boundaries and the user has full control at all times of the definition parameters used.  The analysis functions can further be used to validate the results by verifying continuity between surfaces and analysing deviations between the surfaces reconstructed and the original scatter of points.  The tools provided today by CATIA V5 solutions allow all types of digitised product to be integrated in a digital mock-up, existing business assets to be further exploited, and complex product design to be accelerated, whatever the area of activity.

Working with Keonys

Keonys can provide the following services for equipping and deploying a reverse engineering process using solutions from Dassault Systèmes:

  • the 3D Optinum scanner from Noomeo.
  • training on all reverse engineering solutions from Dassault Systèmes and their partners, whether for new or more experienced users.
  • our methodology expertise to help you define an effective and productive methodology for your finite element analysis, design optimisation, deviation measurement and machining processes.