Evolving market requirements demand increasingly flexible manufacturing systems. Mathias Bihler (Managing Partner, Otto Bihler Maschinenfabrik) and Markus Sandhöfner (General Manager, B&R Germany) explain how collaboration between OEMs and their automation suppliers can get machine tools up to speed for Industry 4.0 and the Internet of Things.
If there's one thing that pervades every sector of industrial manufacturing, it's the need to produce ever smaller batches more efficiently and economically. Matthias, are you experiencing this trend in the field of metalworking?
Mathias Bihler: Only ten years ago, it was common practice for a company like an automotive manufacturer to award a yearly contract for millions of parts, which would be produced in one go and then sit in the supplier's warehouse. That's a huge amount of capital to have tied up, not yielding any return, and it's anything but economical. So there was a clear motivation to design more responsive equipment with shorter changeover times that would enable just-in-time production.
How can you shorten changeover times for machine tools?
Bihler: With a conventional cam-operated machine? Hardly. After all, the really time-consuming part is the fine tuning. It takes hours, if not days, to dial in the exact pressure to form a part just right. On top of that, it's a finicky task that requires highly specialized personnel. If the specialist you need isn't available, you can't start up your machine. That's simply not compatible with modern just-in-time production.
What's the solution?
Bihler: Our solution was to develop NC machines based on advanced control and servo technology from B&R. With these Bihler NC machines, you define the force or motion profile once and save it on the controller. When you retool the machine, all you have to do is load the corresponding program.
Can you give us an example of how this works?
Bihler: Sure, let's say an automobile manufacturer orders 50,000 stamped parts from one of our customers. As soon as the order comes in, the machine is retooled. With our NC technology that means about fifteen minutes to an hour until they're ready to begin production. Once the run is complete, the machine is retooled again – maybe this time to fill an order from a medical engineering company. This responsiveness is currently revolutionizing the stamping and forming industry. If you ask me, we're going to see the market for traditional cam-operated machinery shrink rapidly over the next few years.
Markus, what solutions does B&R offer for the kind of responsive machinery Matthias is talking about?
Markus Sandhöfner: The performance of these machines doesn't come from any one hardware or software product alone. It emerges from a kind of system integration you won't find in most suppliers' portfolios. An example of this is how B&R completely decouples hardware from software. Once software has been written, it can be used and reused on any generation or performance class of B&R hardware. Another thing that's really important are open interfaces that allow OEMs and system integrators to control all the necessary components with a single system.
Bihler: That's actually a very decisive factor for us. With B&R, we're able to control all the functions we need for automation and process design with one master controller. If you have multiple processing technologies in an integrated line, and each one needs its own controller, the running costs for maintenance and servicing quickly get out of hand, and eventually you run into performance limitations as well.
Speaking of performance: How do servo machines compare with quality cam-operated machines?
Sandhöfner: Today's servo technology far outperforms cam technology. Just look at the new generation of Bihler machines: On one line they have 89 axes synchronized with a cycle time between 400 and 800 microseconds using our real-time POWERLINK network. This allows for an unbelievable level of precision.
Bihler: I can certainly attest to that. In efforts to optimize our machines, we push each process to the edge of what is physically possible. Our bending processes are so fast that we're just barely within the material's plastic deformation capacity.
How is that possible?
Bihler: To really explore the limits of our machines, we used to go through countless iterations of cam design – calculating, prototyping, evaluating and recalculating. With servo technology, I can tune a profile to the precise deformation capacity of a given material in a matter of minutes. But that's not all. Measurements are also performed during the bending process to identify any deviations from the intended angle – for example due to inconsistencies in the material. The combination of B&R servo technology and Bihler instrumentation is so fast, you're able to make the necessary adjustments on the fly. Our customers get the best of both worlds: perfect quality and exceptional productivity.
Such an advanced control solution must require highly specialized software development.
Bihler: That it does. A large portion of our NC machines' success can surely be attributed to our expertise in the areas of stamping, bending and assembly processes. At the same time, though, when it comes to motion control, general closed-loop control and much more, we don't need experts. For these things we're able to rely on our automation partner. B&R gives us an ideal platform to make the most of our process know-how.
What does that platform look like?
Bihler: Well, it includes a multitude of hardware components, but of course also the development environment, Automation Studio. And in the future we'll be relying even more heavily on B&R's know-how, for example with the OPC UA interface we're currently implementing. Since all of B&R's controllers can be operated as OPC UA clients and servers, this is astonishingly easy. We'll also be benefiting from B&R solutions when integrating robotics into our machines in the near future. We won't need a dedicated robotics controller, and programming the robots will be extremely simple thanks to mapp.
Markus, can you give us a little background on mapp?
Sandhöfner: mapp Technology encapsulates entire mechatronic solutions in easy-to-use software components, which are ready to go with just a few simple configurations. This enables customers like Bihler to control complex kinematic systems without having to write the motion control software themselves.
Matthias, you mentioned OPC UA. Is that an indication that you're focusing development efforts towards increased networking capability?
Bihler: Absolutely. Connectivity is the lifeblood of advanced manufacturing. It's what concepts like Industry 4.0 and IoT are all about. We've actually made a great deal of progress in this direction. Bihler machines around the world are already sending data to our headquarters for analysis. We're at a point where we can call a customer and tell them a specific bearing in a specific machine is displaying signs of wear and needs to be replaced to avoid unscheduled downtime.
How are you able to pinpoint the problem so precisely?
Bihler: Every axis has a characteristic fingerprint, which we measure and document prior to delivery. If we notice a deviation from this fingerprint, we immediately know that a parameter has changed. This is a striking development. It used to be that when a Bihler machine went down, we'd have to send a service technician to troubleshoot all of its 40 axes. Once he identified the defective part, he'd have to either pick it up himself or have it shipped. There's one thing I'm sure of: Companies that aren't working on ways to collect and analyze data from their machines are going to have a harder and harder time competing around the world.