Once uncommunicative industrial robots and machine tools are now beginning to talk turkey, thanks to a prototype application developed by a team of partner companies led by the National Center for Defense Manufacturing and Machining (NCDMM). This application was successfully demonstrated and tested by manufacturing researchers at the National Institute of Standards and Technology (NIST).
The practical advance stems from a "generic bridge" devised to span a costly, performance-slowing language barrier in factories. In effect, the innovation is a translator that converts data and messages written in two languages—one preferred by robotics researchers, ROS-Industrial, and the other by the builders of machine tools, MTConnect—into a form understandable to both.
The link eliminates the need to do a full-blown conversion of computer codes to get robots and machine tools from different vendors to handle complex interactions smoothly. Instead, using the bridge entails writing the equivalent of a mutually understood introduction—a "wrapper" in software parlance—that makes it possible for the entire message to get through.
In the recent test at NIST, the software innovation enabled a robot conversant in ROS-Industrial to load and unload parts into an MTConnect-talking lathe for cutting, precisely when the machine tool was ready to perform the task.
Without the bridge, such a synchronized interaction would have required many hours—even days—of reprogramming in both languages. With the bridge, coordination between machine tool and lathe was accomplished in a few hours.
"The goal of this project and follow-up efforts is to make it as easy as possible to integrate factory robots and machine tools and also to reconfigure them in response to changes in orders or customer requirements," explains Fred Proctor, leader of NIST's Smart Manufacturing and Construction Control Systems Program.
The communications logjam between robots and machine tools made by different vendors might be surprising to users of everyday electronics and communication equipment. Thanks to widely used standards, smart phones, computers, printers, and a variety of other products have almost effortless "plug and play interoperability." This is not the case for equipment used in manufacturing operations, where operating systems and specifications for communication often are proprietary, Proctor explains.
The "meet-me-in-the-middle approach" for MTConnect and ROS-Industrial appears to be a practical solution to the proprietary-systems hurdle, he adds.
Sponsored by the Association for Manufacturing Technology, MTConnect is a relatively new open-source standard for collecting and communicating real-time information from manufacturing processes and for integrating factory equipment from a variety of vendors. As the number of makers of machine tools and supporting equipment and software adopting the standard rises, the variety of MTConnect applications also is increasing.
ROS-Industrial sprouted from an open-source robot operating system (ROS) originally developed by a group of researchers at the Stanford Artificial Intelligence Laboratory. The grassroots ROS standard simplified the task of linking assorted experimental research robots as well as add-on equipment such as sensors or grippers. A consortium organized by the Southwest Research Institute is now extending ROS to industrial robots and hardening it for manufacturing uses.
NIST funded the development effort at NCDMM, a nonprofit organization that develops and transitions improvements in manufacturing technology to DOD and its suppliers. The NCDMM team consisted of researchers from System Insights, Southwest Research Institute, and the Association for Manufacturing Technology. NIST and its collaborators are now exploring options for testing the generic bridge in a real factory.