Study of Vibration of Electric Power Steering Systems Using a Continuous System Model

Electric power steering systems (EPS) offer better fuel efficiency than hydraulic power steering system. However, EPS systems are plagued with noise and vibrations, which can undermine the comfort of drivers. In previous works, steering systems have been analyzed using two degree of freedom system. In this paper, a mathematical model of an electric power steering system is presented using a continuous system to model the steering column. The equations of motion and boundary conditions are derived using Lagrangian method. Explicit expressions are presented for the characteristic equation and mode shapes. Parametric studies are conducted to study the effects of different parameters on natural frequency.