US Patent 8170780 Apparatus and method for control of a vehicle

An apparatus and method for transporting a payload over a surface is provided. A vehicle supports a payload with a support partially enclosed by an enclosure. Two laterally disposed ground-contacting elements are coupled to at least one of the enclosure or support. A motorized drive is coupled to the ground-contacting elements. A controller coupled to the drive governs the operation of the drive at least in response to the position of the center of gravity of the vehicle to dynamically control balancing of the vehicle.