Browse Publications Technical Papers 2002-01-1580
2002-05-07

4-DOF Vehicle Ride Model 2002-01-1580

Ride quality is one of the most important criteria by which people judge the design of a car. At the most basic level, ride isolation properties are investigated using a quarter vehicle model. But the input from road roughness would excite not only bounce motions, but also pitch motions. Understanding the pitch and bounce motions is essential because it is their combination that determines the vertical and longitudinal vibrations at any point on the vehicle [2].
In this paper, a 4-degree-of-freedom (4-DOF) Vehicle Ride Model, which is shown in Figure 1, is used to investigate the effect on the ride quality of the dynamic index in pitch, mass ratio, weight distribution and flat ride tuning. A Lagrange equation is used to derive the equations of motion. A state-space formulation is obtained by using state variables. From these, the characteristic equation, natural frequency and damping ratio are obtained. Through an analytical and numerical study of the ride quality of a 4-DOF model, the dynamic behavior of a vehicle is investigated by simulating the bounce motion, pitch motion, front secondary suspension force, front shock absorber force, and front and rear wheel hop frequencies. “Magic numbers”[1] are applied to give the right directions.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Quarter Vehicle Ride Model

2002-01-1581

View Details

TECHNICAL PAPER

Analysis of a 4-DOF Vehicle Model Using Bond Graph and Lagrangian Technique

2002-01-0809

View Details

TECHNICAL PAPER

A Passive Nonlinear Damping Design for a Road Race Car Application

2006-01-1984

View Details

X