Take a chart like the one that leads this story, and at least 95 percent of the people looking at it will have no clue what it means. We don’t have the knowledge to make the connections. But put a little algorithm behind it, and it becomes a picture of a workpiece. “Now the Big Data is getting smart. You can understand it and you know maybe you want to change something on your workpiece,” explained Ramona Schindler, machine tool digitalization business development manager for Siemens Industry.
Comparing that smart data to a real workpiece brings even more into focus—perhaps there’s an unwanted groove in the raw material, or the drill being used is too big. “The next step is making an algorithm to automatically tell you that certain workpieces have worse quality,” Schindler said. “You could get a holistic picture of the whole process or of the whole production, so you can directly get the feedback to change something or add something to your process.”
This is the vision of digitalization in the machine tool industry, where increasing global competition and changing customer behavior create an even greater need for the benefits that increased analytical capabilities can provide. As the International Manufacturing Technology Show (IMTS) draws near—running Sept. 10-15 at McCormick Place in Chicago, where machine tools will figure prominently—Schindler spoke recently with industry press to describe the value of digital twins in machine tooling as a preview to the Siemens booth.
Digital twins can focus on the whole life of a product—on machine tools, but also on the products made on the machine tools, she emphasized. In a way, a CAD drawing is already a digital twin of the product. But creating a digital twin of the entire value chain means that you don’t lose any information along the way.
“Connecting these pieces of parts, that’s for me the goal of digitalization—making data available along the whole value chain,” Schindler said, describing digital twins of the product, the production process and the machine tool. “There are lots of digital twins around. The most value can be given if we combine these digital twins.”
From the machine builder’s perspective, digital twins can provide virtual commissioning. To test the machine typically, everything has to run very slowly so that no one is hurt and the tool itself isn’t hurt. “You already have a small digital twin—the CAD drawing. You already know what controller you want to use. So why not use your virtual digital twin of your machine tool to test your program? You don’t hurt anybody, and you don’t hurt the machine,” Schindler suggested. “There are a lot of new ways to experience your machine, test your machine, maybe try out very crazy things because it’s all virtual.”
That experimentation on the virtual machine in turn helps to enrich the original CAD drawing with additional knowledge through the simulated physics, Schindler added. “You can adapt so much without needing the real steel,” she said. “Then when the steel is done, you bring it down to the shop floor and you’re sure it’s working in the right way.”
In addition to simplifying and speeding up the commissioning process, digital twins can be used to provide training to customers while the machine is still being built. “When your machine is delivered to the end user, he’s not losing any time,” Schindler said. The digital twin can also be used to provide practical demonstrations to end users and help with change management, she added.
Maka Systems, a CNC machine manufacturer based in Nersingen, Germany, uses virtual commissioning to shorten the commissioning time of its machines from six weeks to one week. Using Siemens’ Sinumerik 840D sl VC-Rack, Mechatronics Concept Designer (MCD), Simit simulation software and a simulation unit, Maka can verify its PLC and NC programs in a virtual environment while the actual machine is still being built.
It’s all about money, Schindler said. They’re reducing non-productive time on the shop floor, guaranteeing higher machine quality by testing machines and even testing the parts the user wants to make on the machine, and enabling new business models. “Steel is one value they deliver,” she said. “How to make life as easy as possible for the end customer, that’s the next step.”
Of course, those are all benefits for the machine tool user as well. Whether from the machine builder’s or the user’s perspective, it’s really all about having the data and knowing what to do with that data, Schindler said. With the right data, an end customer can change and adapt the variables related to the machine tool, reducing downtime, getting higher part quality and boosting efficiency.
A basic version of the digital twin from Siemens is SinuTrain, which was originally developed to provide training for schools. “A lot of end customers are now using the SinuTrain as an easy simulation tool; as an easy testing tool for programs before they send it down to the shop floor. You can simulate the program or part that you want to run,” Schindler said. “Basically, it’s positive for the end customer because he doesn’t have to use the machine for testing.”
VNCK is a virtual machine that lets customers tackle more complex simulation systems. It operates as a solution for the high-end machine tool market to verify NC programs for Sinumerik 840D.
Siemens will be showing both products at IMTS, in booth 134502 in the east hall. Schindler will also be providing presentations, helping customers get a feel for what a digital twin really means.
