Runway debris scanner uses low profile and high accuracy motor

Faced with the demand for a compact high accuracy motor to drive its breakthrough runway scanning radar system, UK consultancy Plextek selected the XR15-05 direct drive torque motor from Printed Motor Works.

The millimetre wave radar was created to locate the precise position of small foreign objects, such as debris lying on an airport runway.

The company's external rotor motor is suited to driving scanning devices as the scanner can be mounted directly to its outer rotor with no need for a gearbox. This avoids the backlash associated with gearboxes and provides greater positional accuracy.

The devices need to scan slowly over a 90-degree or 180-degree sweep with rock steady smoothness, and then fly back to the start point quickly for the next scan. The motor, therefore, needed to have a rotor with low moment of inertia and enough torque for the fast sweep, deceleration to stop, reverse and fly back.

It also needed to have minimal torque ripple, or cogging, so that it could sweep very smoothly, with no disturbance to the positional accuracy.

"The profile of the XR15-05 was lower than any of the other motors tested by Plextek," said PMW applications engineer Nick Revels.