Professor Ken McConnell is about to make life a bit more difficult for people who rely on the hum of their ink-jet printers to know they’re turned on and working right.

New Robust Vibration Suppression (RVS) technology eliminates the noise usually associated with appliances run by stepper motors and increases how fast they work, McConnell said.

Stepper motors run kitchen appliances, office equipment, industrial robots and other mechanical items such as vending machines and cameras.

The noise from one printer may be considered an irritation rather than a real problem, but when that noise is amplified by multiple printers in an office setting, it can seriously interfere with communication.

Solving the problem was “really extremely simple,” McConnell, professor in aerospace engineering and engineering mechanics, said.

He has been working on the problem since 1988, he said.

Conventional stepper motors “move steadily by jerks,” McConnell said.

Rather than rotating smoothly, the motor makes hundreds of tiny, incremental steps. Each time the mechanism “steps,” it clicks into place, which is where the noise comes from, he said.

Each step also takes time, energy and produces a vibration. The amount of vibration always has been a concern when using stepper motors, he said.

As the motor makes each step, what is propelled by the motor vibrates. The faster the motor turns, the stronger the vibrations; and precision, which is critical in both appliances and robots, is lost.

The problem, known as residual vibrations, is complicated in robots that move various masses. When a robot’s arm is empty, the residual vibrations are at one frequency. After the robot picks up an object to move it, the vibrations will be at a different frequency because of the increased mass, he said.

The ability of a motor to maximize speed and accuracy is known as robustness. By “smoothing out” the steps the motor makes, vibrations are decreased and robustness is increased, McConnell said.

Chad Bouton, former graduate student with degrees in electrical and mechanical engineering, worked with McConnell in developing the speedy, silent and accurate RVS technology, which is now in the process of being patented.

RVS technology, once marketed as a computer chip, will “improve the performance of any machine that moves one part in relation to another,” McConnell said.