ATorqSense transducer is helping ensure the reliability of powered wheelchairs, scooters, golf buggies and other electric vehicles, having been incorporated into a dynamometer rolling road built by PG Drives in Dorset.

PG Drives manufacture black box electronic motor controllers for chair and vehicle builders around the world. Reliability and robustness are paramount as their duty cycle is so unpredictable. Even the least adventurous users are likely to ‘go off road’.

The rolling road measures the torque between the motor and the inertia network it is driving. The TorqSense transducer, which monitors the motor’s performance by constantly measuring the torque at its output shaft, uses surface acoustic waves (SAWs) as frequency dependent strain gauges to measure changes in resonant frequency in the motor’s drive shaft as the test programme is run. A wireless radio frequency coupling is used to transfer the data signal to a pick-up head.

“We often run arduous test regimes for 10hours or more until the battery is flat,” says Dr Richard Gears of PG Drives. “We always have the rig manned for safety. With large currents being generated and the motor regularly overloaded, we can’t risk lights-out overnight testing.”

Enter 36 or 'tick' at www.engineerlive.com/ede

Sensor Technology Ltd is based in Bicester, Oxon, UK. www.sensors.co.uk