Bio-Inspired Artificial Sea Lion Whiskers Could Let Autonomous Vehicles and Drones Find Other Craft
Using a model of sea lions' whiskers these scientists have created a new Time Difference of Arrival (TDoA) sensor for locating disturbances.
A team of scientists at the City University of London has found a way to create artificial whiskers capable of locating the source of flow disturbances in liquids — inspired by the whiskers of sea lions.
"Previous behavioral research on live sea lions has shown that they are able to detect the direction of oncoming vortices, even when impacting contralaterally," the researchers explain by way of background. "These experiments showed that the whisker system and the animal's neural processing is seemingly able to detect the Direction of Arrival (DoA) from just one side of the head's vibrissal pads. Therefore, temporal differences between whisker stimulation is a likely method for determining the angle."
To prove that concept, and to see if it could have applications elsewhere, the team set about replicating the whiskers artificially — building a two-dimensional array of bio-inspired whiskers and a three-dimensional array modeled after a sea lion's head. Inserting the arrays into a water tank with a vortex generator, the team proves that their model of how the whiskers worked seemed sound — and the artificial versions could, indeed, use Time Difference of Arrival (TDoA) to detect the source of the disturbance.
"A regular [2D] array attached to a plate is a more practical deployment of the sensors for future applications," the team concludes, "including autonomous underwater navigation and tracking systems. Taking multiple triplets of sensors leads to an over-determined system, which produces more accurate solutions by combining the output of all suitable triplets. In addition, machine learning or training methods may further improve the systems reliability, and reduce its sensitivity to noise. The regular pattern of the array was used as a simple layout to ensure the vortex pulse could be picked up reliably."
The team is also working on moving the concept out of the water and into the air, building an airfoil equipped with their artificial whisker array in order to monitor airflow — hoping that the same calculations, which found the source of the disturbance in water, will allow them to locate other aircraft from their wakes.
The team's wok has been published under open-access in the journal Nature: Scientific Reports.