Researchers at the University of California San Diego (UCSD) have found a way to make robots perform better on uneven terrain that normally proves a challenge for wheeled as well as legged robots. This could potentially change how we use robots, opening up a host of new uses – from industrial activities and search-and-rescue missions to perhaps even the exploration of other planets and asteroids.
The UCSD team has managed this via the use of flexible spheres made of latex that are filled with coffee grounds and other ‘structures’ (inspired by plant roots and man-made methods of securing structures). This allows a robot to have better grip on uneven surfaces by letting the ‘foot’ mould itself to the terrain. According to the team behind this innovation, this works on the principle of ‘granular jamming’, with the coffee grounds transitioning between a solid and liquid-like state: When the feet are raised, the grounds are loose and ready to adapt to the surface; when placed on the ground, the feet become firm and conform to the surface underneath, providing a stable grip.
“Usually, robots are only able to control motion at specific joints,” explained Professor Michael T. Tolley of the UCSD’s Department of Mechanical and Aerospace Engineering. “In this work, we showed that a robot that can control the stiffness, and hence the shape, of its feet outperforms traditional designs and is able to adapt to a wide variety of terrains.”
The new feet were fitted to a hexapod robot, which was tested on a range of surfaces, from flat ground and sand to pebbles and wood chips. The team also compared active jamming (using a vacuum pump to firm up the robot’s feet) to passive jamming (relying on the robot’s weight) – it seems passive lamming works better on flat surfaces, while active jamming offers greater stability on loose rocks.
How much of a difference do these feet make? The UCSD researchers estimate that these flexible feet could help robots walk up to 40% faster on uneven terrain, which could possibly offer a massive boost for outdoor and industrial usage. Future plans include fitting flexi-feet robots with surface-sensing tech, which could enable autonomous usage by allowing the robot to configure itself for operation in unknown terrain without human intervention.