Swiss researchers are working on an environmental monitoring robot named Avocado that’s been inspired by abseiling spiders. The fruit-shaped bot uses a winch and rotors to lower itself through the canopy and gather data on life in the treetops.
The prototype from ETH Zurich’s Environmental Robotics lab features a winch housed within the upper section of its 3D-printed frame and two ducted three-blade props side by side in its girth below – giving it the outward appearance of a large avocado.
The idea is to tether the robot to a branch high in the canopy, and have it lower itself through the crown using a battery-powered servo controlling a winch. There’s a camera at the bottom of the frame, and if an obstacle is detected on the way down the props are fired up to maneuver Avocado around.
This is said to give the abseiling bot some advantages over existing monitoring techniques. Using flying drones, for example, risks them getting entangled in thick foliage, while climbing bots could find it challenging to navigate past different-sized branches or maintain grip on slippy surfaces. Avocado could also allow research teams more scope to explore a wider range.
At the moment, the prototype has been lab tested on a predefined obstacle course, as well as on a tree in the great outdoors. The setup “has fully mastered autonomous locomotion” but currently requires someone to climb up high and tether the bot to a tree.
However, it could be mounted underneath a drone flying to otherwise inaccessible areas before securing it high in the treetops so it can lower itself down and get to work. The design allows for the robot to take various instruments along for the ride, such as environmental sensors or even a gripper for collecting samples. And though its systems are powered by batteries at the moment, future iterations could see the tether topped by a solar cell to send power through the winch cable to the robot and sensor suite below, enabling longer missions.
The project has been funded by the Swiss National Science Foundation, and the research team is part of an ETH group that’s made it to the finals of the XPrize Rainforest competition – which looks to reward projects aimed at furthering “our understanding of the rainforest ecosystem” with a share of the US$10-million prize pot.
A paper published last year is available to view online. The video below has more.
AVOCADO: Multimodal Aerial-Tethered Robot for Tree Canopy Exploration
