Abstract
As a vehicle speed increases, roll natural frequency modes changes from that around its roll axis to that around its center of gravity of its body. To understand this phenomenon, the illustrated method for the change of roll natural frequency is proposed. Further a characteristic equation is considered and the combination of four kinds of design parameters which determine roll character frequency is found out. Parameter study was performed about the influence which the combination of those parameters has on roll natural frequency. As a result, the change of roll character frequency was understood.
