Using photogrammetric modeling in reverse engineering applications: Damaged turbocharger example

Abstract

Engineering in different areas such as design, manufacture, quality control, research and development, damage analysis, etc. increasingly needs fast, detailed and accurate three-dimensional (3D) documentation of mechanical parts. Moreover, not only in the production and design processes, but also in the post-production stages, the details of the parts may need to be documented in the exact dimensions. Identifying an assembly's components and their interrelationships, producing new digital 2D-3D models of the assembly or parts, rebuilding a part or assembly, examining parts to ensure quality and tolerances, improving performance and if there are any, determining the damaged sections are some of the essential applications of reverse engineering. The purpose of this article is to demonstrate the implementation of a low cost scanning system to create digital copies of mechanical parts. In this study, a mobile phone-based photogrammetric technique is applied to obtain a 3D model of the damaged turbocharger of a car. Firstly, the turbocharger was dismantled into two parts. Both parts were individually modeled and then assembled together. Thus, the turbo wings under the covers were modeled in detail. Accuracy analysis in terms of dimensions was performed in the obtained model. Finally, a simple CFD application was made on a section of the compressor wheel of the turbocharger. Accuracy analyzes of the 3D models showed that less than 0.5 mm accuracy can be obtained without difficulty.