A mobile base movable relative to a surface is disclosed. The base includes
a main housing having at least two wheels pivotably and rotatably mounted
to the housing with each wheel having a steering axis and a rotation axis.
The steering and rotation axes are nonintersecting and are offset by a
known caster distance. Further, included are drive means for rotating the
wheels to roll along the surface, steering means for pivoting the wheels
and changing their heading with respect to the surface, and controller
means for reading an input vector from a host processor. The input vector
is a three dimensional force torque vector.
