Improvement of Dynamic Wheel Load Oscillations by Coupling Pitch Motion into Bounce Motion during Pitching Motion of Passenger Vehicle

Abstract

The aim of this study is to determine the oscillation center position change that can reduce the dynamic wheel load oscillations during the pitching motion. For this purpose, the pitch and heave motions were coupled to each other during the pitch motion by changing the positions of the pitch and heave oscillation centers according to each other. The degree of coupling is determined by the front and rear spring stiffness. For this, the half-vehicle model that can be coupled to the two-quarter vehicle model with the suspension components were used. With this model, the effects of coupling on dynamic wheel load oscillations were examined in frequency domain according to the location of the center of gravity and vehicle speed. The results showed that the position changes of the oscillation centers can reduce both the front and rear dynamic wheel load oscillations, and this will be slightly affected by vehicle speed variation. It has also been found that this improvement depends on how the damping level of the shock absorber on a wheel will vary with respect to the change in the suspension spring.