Abstract
On-Center handling subjective evaluation by drivers and objective evaluation by low frequency sinusoidal torque input test clarify on-center handling mainly depends on the increasing characteristics both steering torque versus steering angle and steering torque versus yaw velocity from center point of steering. Steering stiffness for driver at the steering wheel decreases from the center point as the steer torque increase by the series of stiffness element and spring-friction elements. Spring-friction elements in the steering system make nonlinear steering stiffness smoother and shorter the delay of wheel steer. Adequate stiffness of steering system and proper friction torque in spring friction elements, proper distribution of the stiffness elements and spring-friction elements enable to realize the higher steering stiffness from the center point of steering.
