A new perspective on integrated vision
Manufacturing companies are increasingly turning to machine vision systems to support their quality control and documentation processes. Traditionally, however, integrating these systems has been a time-consuming and costly endeavor. Weber Systemtechnik has come up with the ideal solution using a vision system based on POWERLINK.
The quality and documentation requirements facing industry have increased. Using machine vision systems, however, manufacturers can meet this challenge head-on. Nowadays, entry-level intelligent cameras with impressive functionality are already available for less than 2,000 euros. What's more, the software behind these systems no longer requires laborious programming in high-level languages, but instead is a convenient matter of setting parameters. "We have used the momentum built up in recent years to strengthen our position as a provider of complete vision systems for the pharmaceutical and food and beverage industries," says Thorsten Rauber, product manager for measurement and testing systems at Weber Systemtechnik. Located in the German town of Wetzlar, Weber Systemtechnik is one of the first partner system integrators (PSI) to work with Cognex and has used the American company's systems exclusively for 18 years.
Simple integration of cameras
The intelligent cameras from the Cognex In-Sight 7000 series are the first machine vision system in the world to support the POWERLINK protocol. In 2010, Cognex and B&R entered into a partnership which, according to Rauber, has contributed significantly to the increasingly widespread implementation of machine vision. "For the first time, both process and image data can be transmitted via the same medium." Traditionally, two separate networks have been needed. "This simplifies the process of integrating cameras into automation systems and increases the acceptance of machine vision systems among OEMs," continues Rauber.
The real-time Ethernet POWERLINK connection means that instead of transmitting simple trigger signals, the system can send more detailed positioning data to the motion axes. As a result, movement sequences can be coordinated with much greater precision.
Easy implementation and maintenance
Production control and quality assurance processes in industrial applications also stand to benefit from merging machine vision, control logic, I/O and motion into a flexible, coordinated solution. The result is simplified implementation and maintenance, which was a convincing argument for the Weber specialists. It is now the way they prefer to automate the system solutions they develop.
One of these system solutions is an alignment control system for cylindrical objects such as champagne bottles and is particularly useful in filling and labeling machines. At its heart is an industrial PC from B&R's Automation PC 910 series, which is used to run the VisionPro image processing software from Cognex. The system evaluates the data received from the connected cameras to detect registration marks, warning symbols or any other graphical elements and generate a corresponding trigger signal which can be used to coordinate a particular movement.
Accurate positioning down to 0.1 mm
In alignment control applications, the trigger signal is used to line up objects such as champagne bottles so that collar labels can be placed over the neck of the bottle in line with the center of the bottle's main label. The required dynamic rotational movement is provided by a stepper motor that rotates the bottle into position at 3 rpm with a precision of 0.1 mm. The motor (NC axis) is controlled with a stepper motor module and a CPU module – both from B&R's X20 system.
The control functions and Windows-based image processing communicate by means of a PVI interface. Depending on the specific situation, the developers at Weber Systemtechnik use I/O or communication modules from the X20 system to handle communication with higher-level controls. "Thanks to the completely integrated B&R technology, our system is able to adapt very flexibly to the specific requirements of individual applications," explains Rauber. "And it has the performance to easily handle systems with up to 16 cameras."
Industrial PC with no performance limits
Even in a system where not all cameras are sending data at the same time, the control computer must be capable of high processing performance should the need arise. In addition to alignment control, additional functions frequently need to be integrated such as reading and verifying 2D product codes. "Particularly with our 360° inspection system for cylindrical containers, we have run into performance limits using the PCs previously supplied by other vendors," notes Rauber. However, this wasn't the only reason Weber Systemtechnik began looking for alternatives and ultimately selected the Automation PC 910.
"With the Automation PC from B&R, you might say it was love at first sight. We were even convinced by the hardware configuration alone. Yet, what is equally important now is the fact that our customers can get them anywhere in the world thanks to B&Rs international network of offices," says Rauber. He is also very pleased with the stability that B&R provides. "The configuration of the PCs we used in the past was constantly changing, and we were continually having to modify and adjust our systems to keep up. Thanks to the Automation PC 910 and its guaranteed long-term availability, this simply isn't an issue anymore."
Instead, the experts at Weber Systemtechnik can focus their full attention on developing new functions and applications. Their positive experiences with the technology and support provided by B&R prompted Weber Systemtechnik to switch the inspection systems in their own production facility over to B&R solutions. "This way our customers benefit from the combined expertise of B&R and Weber Systemtechnik," says Rauber.
One of Weber Systemtechnik's system solutions is an alignment control system for monitoring cylindrical objects such as champagne bottles and is particularly useful in filling and labeling machines. At the heart of this system is an industrial PC from B&R's Automation PC 910 series, which is used to run the VisionPro image processing software from Cognex. (Source: Franz Roßmann)
The intelligent cameras from the Cognex In-Sight 7000 series are the first machine vision system in the world to support the POWERLINK protocol. For the first time, both process and image data can be transmitted via the same medium instead of using two separate networks. The fast, real-time Ethernet POWERLINK connection means that instead of transmitting simple trigger signals, the system can also send more detailed positioning data to the motion axes. As a result, movement sequences can be coordinated with much greater precision.