Abstract
When viscous damping of a steering system is too little, the steering system becomes vibrating in high speed. When the viscous damping is excessive, a response of a vehicle becomes slow. Therefore the optimal value of viscous damping must exist. To obtain insight of the influence of the viscous damping on dynamic behavior of vehicle and steering system, this paper formulates the natural frequencies and their damping ratios taken account of the viscus damping under force control. One of the formulas implies larger viscus damping of steering system reduces the fast response of vehicle. Finally, this paper studies optimal damping ratio of steering system from the angle of oscillationless behavior, over shoot and delay of vehicle response.
