Software Tool Rejects Process Disturbances

Here's a chance to reject process disturbances in control systems before they degrade plant performance. Control-systems software company LineStream Technologies Inc., of Cleveland, has worked with Cleveland State University to produce a software tool designed to automatically tune manufacturing processes before disturbances can cause problems.

Manufacturing processes face variables such as material inconsistencies, ambient temperature swings, vibration, and friction. LineStream's software tool, InTAC, was created to neutralize these inconsistencies before they do harm. The company says the optimized performance can reduce energy consumption by as much as 50 percent.

Proving the concept at an actual plant
LineStream validated InTAC at a Parker Hannifin hose extrusion facility in Ravenna, Ohio. The plant's general manager cited immediate power savings, saying the meter readouts "looked like they fell off a cliff, reducing power consumption by 57 percent."

The plant's senior manufacturing engineer, Scott Burrowbridge, says he saw improvements in maintaining consistent heat. "In our heating application, the temperature controller calls for heat," he told me recently.

"It would overshoot and undershoot. So we had a system of heat and cooling to maintain the desired temperature." He noted the LineStream algorithm got rid of the overshooting and the undershooting. "We no longer need cooling to bring down the overshoot," he said. "We need less heat and almost no cooling."

According to Burrowbridge, the plant had been using a standard proportional integral-derivative (PID) as a temperature controller: "They've been around forever." After the success of using InTAC, Burrowbridge expanded the new tool to multiple lines, each time repeating an energy savings of 50 percent.

LineStream was incubated inside Cleveland University for over 10 years. Company president, Dave Neundorfer, spun the company out to the private sector in 2008. "The work for InTAC was done at the university, spearheaded by a professor who wanted a better way to deal with disturbances and motor control," he told me. "Control systems are hard to keep in tune to deal with the processes."

InTAC was designed to estimate and reduce process disturbances in real time. "It detects when a distributed process is burgeoning, it estimates the effects, and it sends data back to the controller to neutralize it," said Neundorfer. "It's an early warning system that takes the warning and uses it to eliminate the error."

The company has also developed a second product, SpinTAC, specifically for motor control applications. "SpinTAC applies to washing machines, dryers, HVAC systems, anything that needs a motor to run," he said.