dr. ir. Joaquin Vanschoren

InfraWatchterabyte-scale sensor network analysis

Hollandse Brug

Hollandse BrugBridge deck weakened, heavy traffic bannedComplete deck replaced

Sensor network to monitor bridge behavior

Stress (longitudinal)

Stress (longitudinal)

Stress (longitudinal)

Stress (transverse)

Stress (longitudinal)

Stress (transverse)

Vibration

Stress (longitudinal)

Stress (transverse)

Vibration

Stress (longitudinal)

Stress (transverse)

Vibration

Temperature

Stress (longitudinal)

Stress (transverse)

Vibration

Temperature

Stress (longitudinal)

Stress (transverse)

145 sensors, 100Hz: 5GB/day

Vibration

Temperature

Stress (longitudinal)

Stress (transverse)

InfraWatch project

• Model bridge behavior

• Effects of traffic, weather,... (short term) - warnings

• Effects of decay (long term)

• Interplay between effects (e.g. temp vs stress)

• Optimal sensor network (for new bridges)

• Additional sensors (e.g. chloride)

Enter Hadoop

• Terabyte-scale data analysis (I/O bound)

• Typical MapReduce (Hadoop) case!

• No Hadoop libraries for signal processing?

• Mahout (in progress) general data mining

• Some math libraries (in progress, mostly for calculating Pi(?))

Enter Hadoop

• We need new building blocks:

• Convolution

• Discrete Fourier Transform

• Segmentation

• Modified classification, clustering,... algorithms

• Let’s start coding...

A typical day

• Cars, trucks, traffic jams

• Lots of noise

Smoothing

• Remove noise by convolution with Gaussian response function

Smoothing

• Remove noise by convolution with Gaussian response function

Smoothing

• Remove noise by convolution with Gaussian response function