By Dan Hebert, PE, Senior Technical Editor
Because an embedded automation system is custom-designed for the application, it will offer lower cost, smaller form factor, lower power consumption and higher performance than a general-purpose automation solution. As the degree of customization increases, embedded control advantages become more pronounced, but so do upfront costs and risk.
In its simplest form, embedded control can consist of private labeling general-purpose automation components. The advantages to the machine or robot builder are stronger branding for its products, greater protection of intellectual property, and less likelihood that its customer will specify a particular brand of automation component.
"A common way that machine builders can differentiate themselves with their own controls is to tailor their HMI to reflect their corporate image," says Graham Harris, president of Beckhoff Automation (www.beckhoffautomation.com). "Some of our customers go so far as to include various color options, button configurations, unique bezel designs and more. A great example of a customer that needed a high level of customization is Messer Cutting Systems in Menomonee Falls, Wis. It uses our Panel PCs on its high-performance plasma, oxy fuel and laser cutting machines."
Although this level of custom treatment sounds simple, it requires a lot more upfront work than just buying and configuring an off-the-shelf HMI. Decisions must be made as to the exact nature of the panel's appearance, and once made, these choices are very expensive to rescind or change. Suppliers also typically either charge upfront customization fees, require a customer to make a quantity purchase commitment, or both.
Another reason to go the embedded route is to pack the maximum amount of performance into the smallest possible space. "An autonomous underwater submarine was designed, built and tested by a team of undergraduate students at Cornell University," notes Colin McCracken, director of solution architecture at American Portwell Technology (www.portwell.com). "The key challenge was to identify a powerful enough processor that could fit in an 8 in.-wide pressure vessel hull, and handle image-manipulation calculations with enough horsepower left over to steer the vessel clear of hazards. At 6.7 x 6.7 in., the largest embedded motherboard form factor that would fit was our Mini-ITX single-board computer (SBC) with Intel quad-core CPU."
Again, advantages are significant, but upfront design effort is substantial. Instead of buying a controller ready for panel mounting, the design team purchased an SBC, and designed a housing and means for mounting. The SBC also had to be tightly integrated with other off-the-shelf components, creating a highly customized high-performance system.
Suppliers recognize the time, money and risk that a custom design requires, and develop embedded systems that can customize solutions around a standard set of products. "Previously, there were no standard platforms available from manufacturers as series products," says Norbert Hauser, vice president of marketing at Kontron (www.kontron.com). "But our PCIe/104 SBC solution is available as a series product, allowing OEM solutions to enter the market much more quickly."
In the past, at the least, the interaction between the processor and the FPGA had to be individually developed and validated, Hauser adds. "This effort is reduced noticeably with the availability of our multichip module, which combines an Intel Atom processor with an Altera FPGA. Implementation is further simplified by the standard PCIe/104 form factor."
Another important advantage of embedded control is low cost, not in terms of initial design, but on a per-piece basis going forward. China is the center of low-cost manufacturing, and electronics manufacturing services provider Foxconn recently selected an inexpensive embedded control solution for its China-based manufacturing machinery.
"Our embedded programmable automation controllers, motion controllers and flat-panel monitors were used to build up robotic systems for Foxconn's electronics enclosure assembly lines," says Allen Chen, product manager, Advantech Asia (www.advantech.com).