Dynamics analysis and control of a holonomic vehicle with a continuously variable transmission

This paper presents kinematic and dynamic analysis of a holonomic vehicle with continuously-variable transmission. Four ball wheels, independently actuated by DC motors, enable for moving the vehicle in any direction within the plane and rotating it around its center. The angle between the two beams holding the balls can be changed to alter the gear ratio and other dynamical characteristics of the vehicle. This feature is exploited in augmenting the vehicle stability, optimizing output power, selecting an appropriate gear ratio, and in impedance matching. A simple adaptive friction-compensation-based controller is proposed to handle the complex friction properties.