Researchers build a drone that navigates with physical whiskers to operate in dark, dusty or smoky places where cameras or GPS can fail — sub-100 gram drones run 34KB software to enable sub-mill

A team of researchers from The Netherlands' Delft University of Technology built a lightweight whisker-based tactile sensor that allowed drones to navigate purely by touch. According to TechXplore, the system is designed for tiny autonomous robots weighing under 3.5 ounces or 100 grams, which face challenges in carrying heavy sensors, processors, and power sources, while sensors such as cameras, rangefinders, and LiDAR often have trouble navigating in poor conditions, such as dark environments or dust- and smoke-filled areas.

Here, we aim to equip drones with rich tactile sensing - not for manipulation in the air, but for a novel concept of tactile navigation: using touch to explore and fly through the unknown," Associate Professor of Aerial Physical Interaction and Embodied Intelligence Dr. Salua Hamaza told the publication. But this comes with a challenge: for tactile sensing to work on drones, it needs to be lightweight, low-latency, and low-power. Inspired by nature, we found the answer in whiskers."

Rodents and other small mammals use vibrissae, more commonly known as whiskers, to navigate in tight and dark spaces with low visibility. So, the team emulated this capability by attaching two whiskers to the front of the drone pointed upwards at an angle, with each one connected to three miniature pressure sensors at the base. As the whisker contacts a surface, the changes in each of the pressure sensors allow the drone to estimate its relative depth and location. The drone can then estimate the surrounding surfaces to avoid obstacles, follow the surface, and even map the area based on what it can feel.

Another challenge with equipping drones with whiskers is that airflow could potentially disrupt the system. So, the researchers built a lightweight, real-time processing pipeline that accounts for these minute changes and gives the whiskers millimetric precision. What's more interesting is that this program, which can separate turbulence from surface detection, only uses 34 kilobytes of memory. We wanted to show that touch does not have to come at the cost of size or computational power," researcher Chaoxiang Ye told TechXplore. Our entire tactile perception pipeline runs onboard using just 34 kilobytes of memory, allowing a tiny drone to sense and respond to its environment in real time."

While this lightweight system won't be useful for the world's fastest drone, it's still a great option for tiny drones designed for search-and-rescue operations. Rescue units equipped with these tiny drones could deploy them onsite to explore collapsed structures without endangering people or animals and would even pair well with this 3D-printed cyborg cockroach designed for rescue operations.