  As a single-track mobile platform, bikebot (i.e., bicycle-based robot) has
attractive navigation capability to pass through narrow, off-road terrain with
high-speed and high-energy efficiency. However, running crossing step-like
obstacles creates challenges for intrinsically unstable, underactuated
bikebots. This paper presents a novel autonomous bikebot control with assistive
leg actuation to navigate crossing obstacles. The proposed design integrates
the external/internal convertible-based control with leg-assisted impulse
control. The leg-terrain interaction generates assistive impulsive torques to
help maintain the navigation and balance capability when running across
obstacles. The control performance is analyzed and guaranteed. The experimental
results confirm that under the control design, the bikebot can smoothly run
crossing multiple step-like obstacles with height more than one third of the
wheel radius. The comparison results demonstrate the superior performance than
those under only the velocity and steering control without leg assistive
impulsive actuation.
