More robots migrate to PC-based controls

It's a compelling concept: Use an inexpensive PC to control the axes of a robot but do so in a way that avoids the cost of a Windows operating system. followed in fielding a new robot for the injection-molding industry. No question PC-based controls have become more widely used in motion control, but "We'd been leery of them because of Windows," says AAC Product Development Manager David Lee. ACC specifically didn't like the licensing fees involved or the need to stay current with new versions of the operating system. The latter point could involve significant effort over the average 10-yr life of an industrial robot. The way around this dilemma was through an approach that used the Linux open source operating system. For its new Raptor Series robots, ACC handles motion control and work-cell functions through a PC-based platform from , Santa Barbara, Calif. The real-time version of Linux running on the MEI board "gives us more control of our destiny," explains Lee. "We can customize the kernel as necessary and use only the parts of the software we need. Plus relying on an outside supplier for motion control lets us be experts in building robots and not in building motion platforms." Off-loading motion control to a card also let ACC use a less powerful PC to handle the balance of chores for the work cell. Besides serving as an operator terminal, the PC permits interactions with I/O through the same interface that handles servo axes. ACC also uses this capability to give custom molders a way to quickly change their production setup, thus shortening turnaround time for new jobs. "When a mold is open, it is considered downtime," explains Steve Braig, ACC president. "The goal is to have the mold always full and making product, so we want to reduce