Signal Processing and Imaging

Thanks to recent technological advances, video cameras now have the ability to capture high-density temporal image sequences at a relatively low cost.

In this project, in collaboration with the I4S team, we aim to estimate the movement of the beam from the variations in grayscale levels of the structure’s boundary pixels (or the pixels of targets placed on the structure).

The motion estimation relies on specific image processing techniques, the most well-known of which are based on Digital Image Correlation (DIC).

Ultimately, some image pixels could serve as sensors for Structural Health Monitoring (SHM), potentially replacing traditional sensors such as accelerometers.

This approach is being tested in the laboratory on a vertical cantilever beam, which is excited at its base with white noise using a shaker table. The displacements estimated via image processing are compared with laser displacement sensors. Additionally, the beam’s natural modes and resonance frequencies are identified using a periodogram.

The I4S team can then perform a more detailed modal analysis through signal processing.