Detecting dead wood

Citation

(2001), "Detecting dead wood", Sensor Review, Vol. 21 No. 3. https://doi.org/10.1108/sr.2001.08721caf.010

Detecting dead wood

Detecting dead woodKeywords: Vibration, Sensors

The traditional method of checking crossarms on wooden power poles for rot has been to climb the pole and hit the crossarm with a hammer, then listen for the sound of dead wood. A new method developed at Georgia Institute of Technology is much cheaper ($5/pole rather than $50) and quicker. It bounces a laser from a Doppler vibrometer sensor mounted off the crossarm. The vibrometer rides in a helicopter. The returning beam gives the crossarm's response to vibrations from the helicopter's rotors and engine. Researchers theorised that damaged wood would vibrate differently than healthy wood. Tests proved them right. The researchers then trained a neural network to tell whether crossarms were healthy or ready to break based on the vibration spectra. They further tested and refined the system by using it on 10,000 crossarms.