Smartphones can be used to detect the structural integrity of a bridge: Study – Times of India

To check the physical condition of a bridge, governments need to attach expensive sensors to the structures. However, this is going to change as a recent study has discovered that smartphones can also be used to find out the structural integrity data of a bridge. A new study published in Nature by the Massachusetts Institute of Technology (MIT) claims that mobile phones placed in vehicles can be equipped with special software that can collect data from the bridge. The scientists have developed an Android app that collects accelerometer data from the devices placed in vehicles passing over the bridge. This research was conducted at the Golden Gate Bridge in the US as well as at a smaller bridge in Italy.
How does the technology work
The study explains that a new method to extract “modal vibration frequencies from noisy data” has been designed and this data can be collected from the accelerometers available on smartphones. The data from several trips over a bridge helps the researchers to collect the “underlying dominant frequencies” by cancelling out other surrounding noises generated by — engines, traffic vibrations, asphalt and more.

While conducting the study on the Golden Gate Bridge, the researchers drove over the bridge 102 times with their devices running the software and also collected data from 72 Uber drivers with the app activated on their phones. These data were then compared with the one retrieved from a group of 240 sensors which was deployed on the bridge for three months.
The experts found both data to be largely similar for the Golden Gate Bridge. However, the data from the smaller bridge in Italy didn’t match both types of sensors. Researchers concluded that only an adequate number of trips over a few weeks will be enough to collect important data about the modal frequencies of the bridge.
The research also mentioned that the technology needs more development before it can be scaled up for more users. The data from smartphones will not be as accurate as the one produced by the sensors attached to the bridge, but this technology can help as an early-warning system.