Fast and flexible: This is how quality control works with the LBR iisy

FMO specializes in the field of plastic finishing. We can offer customers all coating steps, but also pad printing and much more – everything that comes after injection molding. For example, we laser six to seven million bus connectors with DataMatrix codes every year. Automation plays a very important role for us, especially in view of the shortage of skilled workers. Four years ago, we put the first KUKA robot into operation, which is responsible for equipping a laser system, among other things. The second KUKA robot, which we received two years ago, can turn, measure, and laser parts. Both belong to the KR CYBERTECH series. I have been interested in collaborative robots that work directly with humans for a long time. But in the past, prices were not attractive. At a trade fair in Kassel, I met KUKA sales engineer Robert Korte, who introduced me to the LBR iisy.

I took a look at the LBR iisy at the KUKA plant in Siegen. Here, I convinced myself of its advantages, such as its ease of use, flexibility and safety features with regard to the employees, and decided to buy it straight away. The order was placed easily and conveniently via the Marketplace. By that time, the exact task for the Cobot in our production had not even been decided yet. As a small medium-sized company, we often don't know what tasks we'll be facing next. The LBR iisy combines various factors that we need therefore: Flexibility, easy programmability and collaborative readiness.

Employees could have done that. In the past, it used to be all done by hand. But it's hard to find someone to do these pick-and-place tasks. It also takes longer and is less accurate. Someone has to take the parts out of the tray, a kind of tablet, for scanning and put them back. And if something goes wrong and a bus connector with incorrect code is used, it can cost much money. That's because these bus connectors are used as the very first part of the control system. Each one is soldered, screwed onto a circuit board, and the entire control system is installed on top of it. If the DataMatrix code is bad, when will this be noticed? In the outgoing goods section! If you think of a large automation company that builds a lot of controls, you know what kind of damage can occur.

First, we laser the bus connectors with the help of a robot. The laser has special software that creates 200 new codes in each cycle. Each of these is an eight-digit alphanumeric sequence of numbers. Then, for quality control, the tray with the 200 bus connectors is moved under the LBR iisy with its two cameras. In the first step, the quality of the codes is randomly checked using 20 parts. If all of them are good enough, i.e. they are rated A or B, the cobot moves over the tray again and checks whether all the codes are readable. If a part is now rated C, it is considered defect and is sorted out. If a part has a C-quality code, the LBR iisy stops and indicates which bus connector is affected. A human colleague can then replace the faulty part. We restart and run everything again until each bus connector is rated A and B.