Turbochargers compress the combustion air supplied to engines. Compared to naturally aspirated engines, this allows higher engine performance to be achieved with lower fuel consumption and better emission values. It goes without saying that the quality of these products must be absolutely flawless in view of the high loads they are subjected to over many years of use.
A new machine vision system called Resident 1200 Visual Inspection designed by the German automation solutions and multidimensional machine vision expert Vision On Line has recently been installed at the development center and production plant of a leading global supplier of exhaust turbochargers for passenger cars and commercial vehicles, ensuring a fully automated 100% inspection of complete turbocharger assemblies and a reliable final inspection shortly before dispatch to the OEM.
Before the Vision On Line system was installed, two employees were used for this task in accordance with the dual control principle to inspect the manufactured turbochargers. These manual checks were not economical and were also more error-prone than an automated quality inspection. As customer complaints can quickly result in very high administration costs if errors are not detected, the manufacturer was keen to optimize this process step last year.
It is no coincidence that the turbocharger manufacturer relied on the support of Vision On Line for this project: Vision On Line has been working with this company for several years and is now approved as a machine vision supplier for many of its sites.
“In close cooperation with our customer’s technical experts, we have implemented the integration of machine vision libraries into their PC-based automation system, among other things,” explains Vision On Line Managing Director Andreas Schaarschmidt. “In this way, machine vision is now deeply embedded in the turbocharger manufacturer’s system without an additional interface and covers the entire range of functions required, from conventional tools to AI applications.”
In the case of turbocharger testing, the automation experts from Langenselbold had to put together a comprehensive package in order to examine all the required features.
“Turbochargers are highly complex components with numerous details that have to be scrutinized as part of the complete quality inspection we wanted,” emphasizes Schaarschmidt. “This includes inspecting the components used, such as the turbine, the boost pressure control flap, the gap between the housing and turbine wheel, geometric specifications and many other details. Without an additional interface, we have integrated the machine vision libraries into the turbocharger manufacturer’s PC-based automation system and cover the entire range of functions required, from conventional tools to AI applications.“
In addition to the complete automation of the test cell and the desired 100% inspection, another challenge for Vision On Line was to ensure the documentation of both the results and the recorded images. It was also necessary to ensure that the system was flexible enough to be able to make individual adjustments in case of any product changes.
Based on these specifications, Vision On Line first created a concept for its customer and then took over the design, the special machine construction, the integration of all cameras and lighting, including the necessary brackets, and supported the customer with the programming. The final programming of the control technology and machine vision inspection was then carried out by the user himself.
Powerful Solution
A sophisticated machine vision system is an essential part of the system. A total of eight exo264 and exo183 industrial cameras from SVS-Vistek are in use.
“These GigE cameras have a number of technical features that make them particularly suitable for this application,” explains Oliver Herrmann, also Managing Director of Vision On Line and responsible for the CAD design of the systems. “One very special feature is the ability to operate the lighting integrated in the system directly from the cameras. This allowed us to implement the machine vision part without the flash controllers that are usually required, thus reducing costs and effort for the user.”
Vision On Line cites the high resolutions of 5 or up to 31 megapixels as further advantages of the SVS-Vistek cameras used, which reliably deliver high image quality and thus provide the optimum basis for the subsequent evaluation of the images. This is carried out using the Halcon image processing software from MVTec on industrial PCs from Siemens.
“Based on the international standards used in the image processing library, this setup allows full freedom in terms of image acquisition in 2D, 2.5D and 3D as well as the optional integration of various standard technologies such as pattern projection, shape from shading or artificial intelligence methods. This made it possible to meet all of the user’s specified requirements for fast processing and thus create the basis for short cycle times,” says Herrmann. “With this system and the selection of integrated components, we were able to achieve an optimal cost-benefit ratio and implement an overall system that is also open to technology and flexible for future requirements.”
Machine Vision as a Key Technology
Machine vision has increasingly developed into a key technology for the turbocharger manufacturer in recent years, emphasizes a company representative: “Industrial machine vision is essential for quality assurance in turbocharger production. We have countless cameras in use in our production facilities. In order to be able to react quickly to changes in processes and, for example, set up new quality inspection stations, we have a number of in-house machine vision specialists and are constantly expanding their expertise with the support of Vision On Line who perform training courses and technical workshops.”
The close partnership with Vision On Line therefore pays off not only in the implementation of current projects, but also in the long term.
