Metal corkscrews are great for opening wine, but who would think they'd also work well as wheels? Tim Lexen, an engineer in Cumberland, Wisconsin — that's who. In his spare time, he built an omnidirectional, all-terrain rover with corkscrew "wheels."
The underbelly of Lexen's prototype includes a flat triangular compartment (7 inches per side), made from PVC, that houses three electric servo motors, battery packs and electronics. These independently operate three 8-inch stainless steel helical coils, which have a low-friction outer coating to keep the device from getting stuck in rough terrain. The corkscrew motion of the coils allows them to push or pull against rugged surfaces, making the robot ideal for roving on textured surfaces such as dirt, sand or gravel.
Such a device could be used to roam the Martian landscape or aid soldiers on Earthly battlefield, but Lexen there are few challenges Lexen needs overcome.
"While significant progress has been made in the development of sensor and control technology, one of the major challenges is that of mobility — that is, physically traversing obstacles, soft and rocky soil and other hazards in complex, unstructured and high-risk environments," Lexen wrote in a paper he presented earlier this month at the IEEE International Conference on Technologies for Practical Robot Applications in Woburn, Massachusetts.
"Most current rover design solutions are improvements over the basic four-wheel or tracked vehicle designs," Lexen wrote. "But these still can be easily foiled in the rover mission."
Helping overcome these obstacles is the prototype's Y-shaped layout and low-friction, rounded edges of the coils. These give the device the ability to move in any direction.
The prototype is currently remotely controlled by a human operator. Lexan plans to add motion sensors so the robot can orient itself, making it suitable for missions requiring independent maneuverability, such as surveillance and search-and-rescue missions.
Photo: Tim Lexen