Additive manufacturing makes it possible to produce components in much smaller runs or even a run of one. Such components are produced from a 3D model using a 3D printer. Such a model can be created using 3D scanners, which have been available for some time. However, creating a 3D scan with a traditional 3D printer is relatively time-consuming and also requires the necessary configuration or data about the object to be scanned. A new 3D scanner from Germany's Fraunhofer Institute for Computer Graphics Research (IGD) changes this. This new scanner can make a 3D scan of any object in real-time, autonomously and without any data about the object to be scanned.
The Fraunhofer Institute points out that components for older products in particular are often no longer produced. As an example, the institute cites a classic car, which is attractive to many users because the vehicle is no longer in production and is therefore rarely seen on public roads. However, this characteristic also poses challenges. For example, if the armrest of a classic car breaks down, it can be a big challenge to get a replacement.
Producing customised parts
However, thanks to Industry 4.0 and the rise of additive manufacturing, it is becoming easier and cheaper to produce customised objects or in very small runs. For this purpose, researchers at the Fraunhofer IGD have developed a new type of 3D scanner. "What is special about our system is that it scans components autonomously and in real-time," explains Pedro Santos, head of the Fraunhofer IGD. This makes it possible to produce a 3D model of a component in a short time, after which this component can be produced using a 3D printer.
In practice, this means that if the owner of a classic car needs a new armrest, the broken one can be reproduced at an affordable price. This involves gluing the broken part to reconstruct it, after which a 3D model of the object is created using the 3D scanner. This model is then produced using a 3D printer, after which it can be covered with leather, for example, or fitted directly into the vehicle.
Both rotary table and scanning equipment rotate
3D scanners, as mentioned, are not new. Many 3D scanners consist of a scanning device and a rotary table. This table rotates the object so that the scanning equipment can image the object from all angles. What is striking about the 3D scanner from the Fraunhofer IGD is that not only the turntable rotates, but also the scanning equipment. For this, the scanning equipment is attached to a robotic arm, which rotates the equipment around the object. Because both the turntable and the robotic arm rotate, the number of rotations the scanner has to make to fully map the object is reduced. This approach reduces the time needed to scan the object compared to traditional 3D scanners. The Fraunhofer IGD states that - depending on the complexity and dimensions - an object can be scanned in a few seconds to a few minutes.
The images taken by the 3D scanner are combined into a 3D model using intelligent algorithms. This model is checked using special software to ensure that the created model is of sufficient quality to make the object 3D printable. If it is, the component can be produced using a 3D printer.
'Intelligent software makes scanner special'
Santos stresses that what is special is not so much the Fraunhofer IGD's scanner, but the intelligent software it uses. During an initial scan, this software calculates exactly which scans are needed to fully image the object as quickly as possible. To determine this, the software does not require any prior information about the object being scanned. This is in contrast to traditional 3D scanners, which require manual learning how to map the object or require a CAD model to determine the position of the object in relation to the scanner. Traditionally, these requirements make 3D scanners less suitable for scanning individual objects and especially for scanning, for example, large quantities of identical car seats for quality control purposes, among others.
The head of the Fraunhofer IGD therefore argues that this intelligence software is a unique selling point of the institute's new 3D scanner. Santos sees opportunities through this clever software to use the 3D scanner to improve the interaction between human workers and machines, something that is the focus of the European Union-funded Autoware project. This project focuses specifically on human-machine interaction during the assembly of cylinders for engines. To date, cylinders are often assembled manually, with final quality control carried out using a checklist and manual measurements. "Our 3D scanning system enables robots - through comparisons with the database - to recognise which component it has in front of it and determine which next component its human colleague needs for the assembly of the cylinder," Santos explains. The machine can also perform final quality control by scanning the cylinder and checking all its dimensions.
Fraunhofer IGD is presenting the scanner at the Hannover Messe, which is being organised from 23 to 27 April in Hannover, Germany. Visitors to the fair can place several objects on the scanner and watch the scanning process live on a monitor. It is also possible to have their own objects scanned using the 3D scanner.
Author: Wouter Hoeffnagel
Source: Fraunhofer Institute for Computer Graphics Research (pictured)
