BMW pioneers robotic automation for mounting gearboxes on engines

Citation

(2002), "BMW pioneers robotic automation for mounting gearboxes on engines", Assembly Automation, Vol. 22 No. 3. https://doi.org/10.1108/aa.2002.03322cab.001

BMW pioneers robotic automation for mounting gearboxes on engines

BMW pioneers robotic automation for mounting gearboxes on engines

Keywords: BMW, Automotive, Gearboxes, Robotics

BMW has installed automation for assembling gearboxes to engines. "It is the first time this has been accomplished anywhere in the world", claims Bernd Bruckert of IBG, the systems integrator responsible for developing the technology. IBG delivered the first cell to BMW's Regensburg plant in February 2002 and will follow it up later this year with another at Dingolfing (see Plate 1).

Plate 1 Systems integrator IBG is supplying BMW with the world's first robot system for automatically mounting gearboxes to engines

"Quality is one of the main reasons for automating the assembly of the gearbox to the engine", says Bernd Bruckert. It is a task that is usually carried out by two operators using an assist device to take the weight. However, performed manually, it is difficult for the operators to feel if they are positioning the gearbox exactly right. "The tolerances are very tight and the operators frequently cause damage", he indicates, warning that, when the operators do not get the position quite right, they are likely to scrape off metal, which becomes debris in the oil. As a result, there could be engine noise and early gearbox wear.

By incorporating vision systems, IBG has enabled the robotic solution to function with maximum precision. One camera is mounted on the robot arm itself and another is stationary. The robot first uses vision to check the position of the gearbox on its carrier before picking it up. Then, once it has the gearbox in its gripper, the robot shows the gearbox to the second camera to determine its exact position in the gripper. It then approaches the engine and uses its on-board camera to check the location of the engine. Having recalculated its program to account for the precise positions of both gearbox and engine, the robot performs the assembly task, putting two bolts in place to secure the assembly. It achieves a tolerance that is tighter than 0.1mm and completes the entire task in a cycle time of just 50sec.

The BMW installation is based around a standard Kuka robot, the KR 200 that has a payload of 200kg. The technical innovation lies in the gripper that IBG has fitted to the robot to handle the gearboxes. Because of the variety of gearboxes, each of which has to be picked up differently (more than 25 different ones are in use at the Regensburg plant), the gripper is highly flexible. In fact, due to the use of servo-controlled location points, a single gripper is able to handle all models. The location points are programmed to move automatically to their new positions, according to the production sequence.

BMW has purchased the rights to the technology IBG developed for the gearbox/engine assembly application and has applied for a patent on it. It relates mainly to the design of the gripper.

Several other vehicle manufacturers are discussing the same application with IBG. Bernd Bruckert is confident of selling a further eight to ten systems within the next two years. He believes that robots are making a comeback in automotive assembly applications. "The robot systems we have today are faster and more accurate than even a few years ago, and they are able to carry heavier loads. It also makes a difference that designers now take into account factors relating to robotics and automation when they do their designs", he comments. It is in the final assembly line where Bernd Bruckert expects to see the most significant increase in robotics in the next few years, particularly for mounting interior components such as cockpits, seats and roof trim.