The Rabbit

Mechanical Systems Design class final project

Our mission was to create a mechanical device, powered by a DC motor and batteries, that simulated the gait of a rabbit and ascended a large ramp.

Our rabbit was driven by a Tamiya Double Gearbox, with a single axle rod transmitting motion evenly to both sides of the device. Our single long motor axle was connected directly to the crank shafts of our back legs, to transmit motion to the back legs' four bar linkage systems. The back axle drove the front axle through parallel soft plastic chains running around two spike sprockets, to drive the front leg four bar linkage systems. Our ear mechanism was attached to the rocker linkage in our front leg mechanism.

Early prototyping done with legos, lego gears and motors.

Summary of analysis done:

MATLAB: Torque and virtual work analysis.

Online Simulation: Used to quickly and easily rearrange single leg configurations and see coupler curves and speeds. This allowed us to virtually prototype legs rapidly, but did not account for depth or coordination between the two legs.

Working Model: Generating 2D motion, seeing interaction between legs.

Human models: Imitating and understanding integrated movement and weight transfer between front and back legs.

Full-scale physical models: Laser cut and hand-machined frames, legs and fasteners.