Drive Train Design Enabling Locomotion Transition of a Small Hybrid Air-Land Vehicle

Design modifications have improved the durability and performance of a previously developed hybrid vehicle capable of both aerial and terrestrial locomotion. Whereas the original vehicle could fly, land!, and crawl in sequence, it suffered from limited durability, as evidenced by catastrophic failure after a small number of landings two to tour depending on the substrate. The two most common failure modes were breakage of the terrestrial locomotion drive servos and separation of components from the fuselage. Evaluation of the original vehicle also identified the need for an autopilot. This further complicated the durability problem by greatly increasing the vehicle's mass, causing larger impulses in high speed landings. The new fuselage design includes a well-defined nacelle to which the propeller motor is securely mounted. All metal DC motors replace R/C servos in the terrestrial drive system, and a slip clutch limits the torque experienced by the motor during landing. The slip clutch comprises an annulus that drives a concentric shaft through three quad profile o-rings. The new 350 gram vehicle has survived eight landings on different substrates with no sign of damage.