Hankook’s research and development center has been working with Harvard engineers and biorobotics experts from Seoul National University on new transformable, origami-like wheels. According to a study published in Science Robotics, these folding tires can drastically alter their structure, diameter and carry heavy loads.
After around ten years of hard work, the team has finally developed a fully functioning set of transformable wheels that can switch between a conventional tall-and-skinny shape and a short-and-fat one. The team attached these wheels to a couple of demo vehicles, demonstrating that the wheels can alter their diameter from 18.1 to 31.5 in (46 to 80 cm) while supporting enough weight to carry a full-size car.
The wheels comprise a three-layer structure based on a thick, flexible composite membrane that folds along similar lines to an origami ‘waterbomb.’ The non-folding panels are sandwiched with laser-cut aluminum facet panels to add wear resistance and structural strength. These panels hold most of the membrane firm, except for the folding lines.
Pressure plates are installed in the wheels to push outwards on the inner hub walls to vary the wheel’s diameter at will. The wheels can collapse to their minimum diameter or fold up to their maximum diameter, where internal locking plates add strength to the structure.
In videos, the team has also demonstrated how the wheels can let tiny robots get low enough to duck under obstacles or high enough to travel smoother and faster. Other prototypes have featured extending bars that fold out as the wheels expand, serving as a climbing apparatus on the wheels to pull a vehicle over ledges that are significantly higher than the wheel diameter.
The team doesn’t imagine these wheels will be commercially competitive, certainly not in their current rugged form. However, their transforming capabilities could come in handy in rovers exploring alien landscapes of extraterrestrial bodies – like the moon or Mars.
If such a rover used wheels like these, the wheels would transfer energy into the ground via kinetic motion more efficiently, preserving power and prolonging the rover’s lifespan.
On that note, Hyundai Motor Group has designed some futuristic walking car concepts that are also ideal for Moon or Mars exploration missions. At CES 2019, Hyundai Motor Group revealed the ‘Elevate’ car concept with wheels attached to robotic legs – allowing users to drive, walk, or climb over extremely rocky terrain.
Earlier this year, Hyundai unveiled a new version of its first-ever four-legged Ultimate Mobility Vehicle (UMV): TIGER, which is short for Transforming Intelligent Ground Excursion Robot. It’s the company’s second UMV design but the first uncrewed UMV concept.
