Camera applications for even more application benefits

IEF-Werner offers camera applications for its palletisers, among other things, which can be used to monitor production processes and ensure the quality of components. Based on industrial image processing systems, they identify the position of a workpiece or certain geometric features, for example. In order to reduce the set-up time of these applications and thus increase the application benefits, the automation specialist developed them further: both the image and the evaluation can be displayed on mobile devices in addition to a central panel.

„Digital camera systems and intelligent methods for image evaluation can be used to significantly reduce production costs and optimise quality control processes," Roland Wertz, Head of Research & Development at IEF-Werner, says. The automation specialist based in Furtwangen in the Black Forest offers, among other things, palletisers that are used in various sectors such as the medical, automotive, semiconductor and watchmaking industries. These enable an organised and gentle transfer of components in modern assembly systems. "We are integrating camera systems into the systems for more and more customers if required," Wertz says. On the one hand, these ensure more efficient handling: for example, a gripper attached to an axis in the palletiser uses image evaluation to determine the exact position of a component on a 40 × 60 centimetre pallet. Or it finds a workpiece that is fed in separately via a vibrating bowl. On the other hand, cameras are used for quality control, for example to identify certain geometric features such as diameter or length.

From simple to complex

In order to support its customers, IEF-Werner has been working on this topic for several years. Initially, the automation specialist relied solely on smart cameras, in which the recorded images are analysed in the device itself. This makes it possible to identify features such as edges or the thickness of a component, as well as the position of workpieces. "This enabled us to solve various pick & place tasks and differentiate between good and bad parts - and we were able to reduce the use of external solutions," Wertz says.  

However, customer requirements have become more complex. What if, for example, chips need to be detected in drilled holes? What does image evaluation look like in difficult lighting situations, for example in the case of transmitted or incident light on metallic bodies - or with dark field illumination? "We expanded our portfolio," the Head of R&D reports. "To do this, we integrated customised image processing scripts into our control system - so the operator has both in one central panel."

The images are analysed using image processing algorithms that can be freely programmed by IEF. This enables the automation specialist to take on and implement even complex tasks - such as identifying very fine components and tiny features in the micrometre range or recognising grey scales using appropriate pre-filtering. IEF-Werner can cover the entire spectrum of its special machine construction, including complex lighting scenarios to recognise micrographs, for example.

Adjustment unit for precise set-up

Telecentric lenses are often used in combination with area scan cameras for measuring tasks. In order to set the depth of field precisely, the operator must adjust them so that the working distance to the object to be identified is set exactly. IEF-Werner offers the domiLINE series for this purpose. The camera - including lens - is mounted on the manual adjustment unit. A precise steel spindle, ball-bearing mounted in an end plate and with a low-backlash, pre-tensioned plastic nut, moves the guide system. Precise positioning is achieved using a rotary knob or a handwheel. The rotary knob is ribbed and - just like the handwheel - has a scale. The unit can be mounted flexibly in all positions. "If there is a product change, the operator can simply readjust the image sensor," Wertz explains.

The challenge so far: the specialist adjusted the camera and then had to check the analyses on the central panel. This is often not located near the camera, but on one side of the system, often in or next to the control cabinet. Several passes are usually necessary until the camera is perfectly adjusted. That takes a lot of time. "We asked ourselves how we could increase the application benefit and user-friendliness of the system in this case," Wertz says. "With our latest development, the employee now also receives the camera image and the analyses based on it on their mobile device via an HMI server." He can stand at the camera and view the camera image directly until he has found the correct setting - this reduces set-up times enormously.

Synchronised position detection

"We offer our customers everything from a single source," Wertz summarises. This is also an important aspect in terms of real-time capability, which could be lost due to network technologies. This is because there were always customers who used their own computers for image processing. This means different operating systems, licences and interfaces. "With our camera system, we can create images synchronised to the position of the component. Monitoring takes place in cycle times of one millisecond. This means that the position is displayed to the user synchronised with the time and can be used accordingly for further analyses," Roland Wertz explains.

Pictures: IEF Werner GmbH

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