Robots carry heavy loads around. They join, weld and assemble parts. That is how smartphones, cars and aircraft are made. But what about the robots – who builds them? One person who is bound to know is Sebastian Bodenmüller, Head of KUKA Robot Assembly in Augsburg.
“When it comes to the production of robots, many of our visitors think of scenes from Hollywood. Our robot assembly facility has nothing to do with science-fiction blockbusters, however,” answers Bodenmüller when asked about the expectations with which most visitors enter the production shops. “That said, we have integrated a wide range of advanced applications,” he adds with a wink. The advanced applications he refers to include, for example, the KMR Forklift – an autonomous transport platform that resembles a fork lift track and is used in the production facility. But more about this later.
Robots are built on a production line
In Augsburg, KUKA produces both series models and small robots. The cycle time is just under 15 minutes. In other words, about four finished robots roll off the production line every hour. The series models, which make up between 60 and 70 percent of our production, are manufactured on an assembly line, while the remaining 30 to 40 percent, including the LBR iiwa, the KR Agilus and the KR Titan, are produced on separate lines or at individual assembly stations. Reasons for this include the weight of the KR Titan, for example, or the complex mechatronic requirements of the LBR iiwa.
It all starts with the mechanical system
The first assembly step for all robots manufactured on the line is assembly of axis 1, comprising the base frame, the gear unit and the so-called rotating column. A flexible robotic cell is available for this. Here, workers can perform screw-fastening and other intricate tasks, while a KR 1000 Titan robot moves the individual parts, some of which are very heavy.
Additionally, a KR Agilus applies sealing compound to the gear unit. After this, the production personnel gradually assemble axes 2 to 6. Together, axes 4, 5 and 6 constitute the complex in-line wrist in which half of the many individual components are installed.
Automation and Industrie 4.0 are put into practice in Augsburg
Like most of the main elements of the robot, the parts for the in-line wrist are produced in the machining shop in Augsburg. The special feature here is a KUKA robot from the QUANTEC series that loads unmachined parts into the machining center in which the elements are manufactured. Between the loading cycles, the robot additionally machines and deburrs components. In this way, all the machining steps that are required for production of the workpiece can be carried out in a single cell.
The screws that are then required for assembly of the finished parts find their way to the right place with the aid of a KMR iiwa. The omnidirectional platform, on which an LBR iiwa is mounted, not only recognizes what screw goes where, with the aid of an RFID scanner, but at the same time knows what goods leave the warehouse when and automatically orders replenishment. It also takes the parts to where they are needed. In this way, the workforce is relieved of tedious sorting tasks.
Time for a splash of color
From a mechanical perspective, the robot is finished. Now is time for the paint. Two booths are available for this. As standard, the robots are painted KUKA orange. If requested by the customer, however, all conceivable colors and patterns are possible, or even flip-flop paint, which changes color depending on the angle from which it is viewed. This also applies to special paint finishes such as foundry paint, that is resistant to heat and acids, or cleanroom paint for sterile applications.
Irrespective of the paint used for the robot, it then has to go to the drying booth. Only then can the water-based, and thus particularly environmentally-friendly, paint dry quickly.
Electrical assembly: the tension mounts
The tension mounts as the robot passes from the paint shop to electrical assembly. Here employees work on the energy supply system and control of the motors. At the end of the cycle time, once the robot has been checked for interference voltage and correct cabling, a fully-automated KMR Forklift takes the assembled robot from electrical assembly to product acceptance.
Thorough check-up in robot acceptance
In product acceptance, the robot is then put through its paces. It is put into operation for an average of 45 minutes so that the oil reaches the right temperature and viscosity. In this way, any leaks are detected at once. Furthermore, the machine data are loaded into the robot here and important measuring tools are mounted on the flange so that the robot can be calibrated. Only when all technical details and requirements are one hundred percent satisfactory can the robot move on to the finish inspection.
Out into the big, wide world
In the final step, the finish inspection, the robot is once again subjected to a thorough visual check. This is followed by application of the warning and instruction signs for robot operation and the identification plate. The robot is then packaged and shipped.
One thing quickly became clear on the tour of KUKA’s robot production facility in Augsburg: it has nothing in common with Hollywood. That said, however, robots working autonomously in the production shops are pretty cool.
Find out more about our robots here.