The rocker-bogie mobility system is a six-wheeled mobility system with the ability to equilibrate ground pressure amongst its wheels and traverse obstacles up to one wheel diameter in height; it has been used previously on NASA's Sojourner, Spirit, Opportunity and Curiosity rovers. This paper presents the mechanical design of an instrumented rocker-bogie mobility system for Kapvik, a 30 kg planetary micro-rover prototype developed for the Canadian Space Agency. The design of the wheel drive system is presented, including: motor selection, gear train selection, and performance limits. The design of a differential mechanism, which minimizes the pitch angle of the rover body, is provided. Design considerations for the integration of single-axis force sensors above the wheel hubs are presented. Structural analysis of the rocker and bogie links is outlined. The cross-hill and uphill-downhill static stability of Kapvik is investigated. Load cell and joint position data from testing during obstacle negotiation and uphill operation are presented.

Additional Metadata
Keywords Kapvik, Mobility system, Planetary rover, Rocker-bogie, Rover chassis
Journal JBIS - Journal of the British Interplanetary Society
Citation
Setterfield, T. (Timothy), Frazier, C. (Cameron), & Ellery, A. (2014). Mechanical design and testing of an instrumented rocker-bogie mobility system for the Kapvik micro-rover. JBIS - Journal of the British Interplanetary Society, 67(3), 96–104.