investigating the behaviour of irings wheels in various operating scenarios
- Paper number
IAC-11,A3,2.P,15,x10641
- Author
Mr. Daniel Oyama, McGill University, Canada
- Coauthor
Mr. Michele Faragalli, Neptec Design Group, Canada
- Coauthor
Prof. Peter Radziszewski, McGill University, Canada
- Coauthor
Mr. Jozsef Kovecses, McGill University, Canada
- Year
2011
- Abstract
In 2009, Radizszewski et al [1] introduced a new class of energy absorbing non-pneumatic, non-rubber wheels. The design consists of a fabric tire carcass filled with rigid spherical particles, mounted on a rim in a manner similar to its rubber analog. It was dubbed iRings in reference to the chain-mail tire material, chosen for space worthiness, durability, and traction on loose soil. At a critical wheel rotational velocity, the primary sustained acceleration experienced by the particles in the iRings wheel transitions from gravitational to centripetal. As the wheel nears its critical speed, the particles begin to orbit the rim, held together by the chain mail. Normal forces no longer have a continuous path from the contact patch to the rim and must now be transmitted via particle collisions. Beyond this critical speed, the wheel exhibits an increase in stiffness along with a reduction in contact area with the soil. Below the critical speed, the particle layer compresses to conform to terrain features. This property of the iRings wheel enables two desired operating scenarios: low speed/high traction for excavation, and high speed/high efficiency for astronaut transportation. This work aims at characterizing the performance of a single 20.3 cm diameter prototype iRings wheel under various speeds and terrain conditions. The wheel is driven about a circular lunar analog surface test bed, while instrumented to determine vertical acceleration, rolling resistance and wheel slip at steady operating conditions. The results show that the performance characteristics of the wheel drastically change about a critical operating speed, yielding multiple applications for this novel wheel design. [1] P. Radziszewski, Martins, S., Faragalli, M., Kaveh-Moghaddam, N., Oyama, D., Briend, R., Prahacs, C., Ouellette, S., Pasini, D., Thomson, V., Lowther, D., Farhat, M., Jones, B., "iRings – Development of a Wheel Prototype Concept for Lunar Mobility," in 15th CASI-Astro conference, May 4th – May 6th, Toronto, Canada, 2010.
- Abstract document
- Manuscript document
(absent)