3D Measuring of Complex Automotive Parts by Multiple Laser Scanning

Abstract

Three-dimensional scanning is available for more than 15 years, however there are few that have heard of it and as few people know the applications of this technology. 3D scanning is also known as 3D digitizing, the name coming from the fact that this is a process that uses a contact or non-contact digitizing probe to capture the objects form and recreate them in a virtual workspace through a very dense network of points (xyz) as a 3D graph representation. Based on this information have been developed many new applications in many fields - computer games industry, prosthetics or forensic medicine, the arts and culture area - but the most common area where scanning systems are used remains the automotive industry, aircraft and consumer goods. Most automotive manufacturers currently use 3D metrology based on optical or laser systems to validate products quality. The pieces are initially measured by 3D scanning then they are compared with the designed model (CAD file) using a specialized software. By this comparison producer can interfere very quickly in the manufacturing process to remove the cause of defects, this technique being called Reverse Engineering (RE). The overall accuracy of a 3D acquisition system depends above all on the sensors precision and on the acquisition device (acquisition with contact) or acquisition structure (acquisition without contact). This accuracy may vary from micron to millimeter and the acquisitions size from a few points to several thousand points per second. In a perfect world or in an integrated production environment, 3D measuring systems should be able to measure all the necessary parameters in a single step without errors, and to render the results in the same way to the manufacturing networks equipped with computers, in formats useful for machines control and processes management.