4-DOF Vehicle Ride Model

2002-01-1580

05/07/2002

Event
SAE 2002 Automotive Dynamics & Stability Conference and Exhibition
Authors Abstract
Content
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.
Meta TagsDetails
DOI
https://doi.org/10.4271/2002-01-1580
Pages
23
Citation
Sun, T., Zhang, Y., and Barak, P., "4-DOF Vehicle Ride Model," SAE Technical Paper 2002-01-1580, 2002, https://doi.org/10.4271/2002-01-1580.
Additional Details
Publisher
Published
May 7, 2002
Product Code
2002-01-1580
Content Type
Technical Paper
Language
English