A Wheel based Stair Climbing Robot with Hopping Mechanism: Numerical Simulations

.Equations of motion


.Body trajectories depending on upper and lower mass ratio


Left: mass ratio of 0.25 and Right: mass ratio of 4.0 (reduced mass of 0.5, spring constant of 2000 N/m, and contraction of spring of 0.1 m)

.Hopping characteristics for initial contraction of spring

With increasing in the initial spring contraction, the hopping height rises, and the axis of the parabolic motion of COM is shifted to the right, but the frequency is not changed.

.Symmetry model