If you attended last month's International Manufacturing Technology Show (IMTS), you might think that you've seen it all when it comes to automation equipment. But wait... there's a disruptive machine control technology you may not see until the next IMTS in 2010 -- active disruptive-rejection control (ADRC). The inventor sees it as a replacement for today's proportional-integral-derivative (PID) control technology.
ADRC, being an active control concept, offers significant user advantages, says the inventor, Cleveland State University's Zhiqiang Gao, associate professor of electrical and computer engineering. Gao says PID's old feedback loop approach can't correct a problem experienced by a machine until product flow is disturbed. "In contrast, the ADRC approach rejects disturbances before operations are affected."
Gao says ADRC's big plus is the ease of operation. "Fine tuning involves one parameter controlled by one knob, a process that can be routinely handled by the machine operator," he notes. "With PID, fine tuning typically involves three parameters, and three knobs, to be set by a PID expert."
The invention is the result of two decades of work at Cleveland State University, explains Gao, who is also head of CSU's Center for Advanced Control Technologies.
"With ADRC we now have a control algorithm solution that will make every machine in a manufacturing process perform better, use less energy and operate more easily," he continues. "Since almost all products are made by machines, the potential impact is rather obvious: better product quality, less energy and material cost and higher productivity."
|Zhiqiang Gao, associate professor of electrical and computer engineering at Cleveland State University, and doctoral student Gang Tian evaluate the performance of a motor's motion control system.|
"PID technology," Gao notes, "dates back to 1922 and it is time to offer the competitive advantage of the latest technology."
Adds Dawson, "We believe this new ADRC technology brings a competitive advantage to manufacturers on two fronts. Initial trials have shown great promise generating a double-digit percentage reduction in errors, which improves on-specification production and overall effectiveness. Savings from higher performance combined with simplified operation and maintenance activities can now be used to improve manufacturers' competitive position in the global market."
With $1 million in financing from Early Stage Partners, a northeast Ohio venture capital firm, Dawson and Gao will pursue beta testing. "Our goal for the next six months," says Dawson, "is to advance from early development to full integration of our controls technology into advanced manufacturing systems. We're excited about the technology and our ability to deliver a competitive edge to all manufacturers, large and small. We believe the technology will help manufacturers remain competitive in the global marketplace without moving overseas."