Automotive, medical and other manufacturers frequently use laser-welding machines to assemble their products. These machines are often preferred for applications requiring precise welding of small components made of different metals.
Trumpf Laser Co. has integrated Cognex vision
sensors into laser welders to improve their welding accuracy and productivity. Photo courtesy Trumpf Laser Co.


Trumpf Laser Co., based in Schramberg, Germany, develops and manufactures these machines and equips them with solid-state lasers. In late 2009, Trumpf began integrating vision sensors into the programmable-focus optics of certain welders to improve their accuracy and productivity. Specifically, Trumpf installed In-Sight 5100 or 5400 vision sensors from Cognex Corp.

To date, Trumpf has installed sensors in more than a dozen machines that are used by manufacturers in diverse industries. All the installations are either retrofits or done on beta machines. Rohwedder AG Vision Technology, a Cognex system integrator based in Markdorf, Germany, installs the sensors.

Prior to welding, PatMax software within the sensor determines the geometric structure of the part to create a three-dimensional image. This data is then sent via Ethernet to the laser’s server, which accurately locates the part and performs laser welding. WinLas software allows easy integration of the sensor to the server.

The sensors are industrial-grade and offer IP6-rated protection against dust and moisture. Protective features include sealed M12 connectors, protective lens covers and stainless steel cases designed to withstand extreme vibration.

The sensors also feature a Windows XP-based operator interface, OCRMax for optical character reading applications, and other measurement- and color-verification tools.

Besides increasing accuracy and productivity, the sensors have enabled Trumpf to reduce production costs and waste. The sensors also eliminate the need for an image processing PC and clamping and positioning devices, which are often used to accurately weld very small parts.

The sensors are small enough to mount directly onto the optics, saving space. Plus, they are user-friendly for operators without prior vision experience and easily retrofit to existing welding machines.

Equally important, the sensors help Trumpf gain new customers. A prospective customer sends sample parts and their welding requirements to Trumpf, which laser welds the parts under production conditions.

The sensors allow fast and accurate welding of the sample parts. The sensors also enable Trumpf to provide the prospective customer with data about the welding application related to accuracy and tolerance (in micrometers).

For more information on vision sensors, call 508-650-3000 or visit