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4-DOF Vehicle Ride Model
ISSN: 0148-7191, e-ISSN: 2688-3627
Published May 07, 2002 by SAE International in United States
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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 .
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” are applied to give the right directions.
|Technical Paper||Quarter Vehicle Ride Model|
|Technical Paper||Analysis of a 4-DOF Vehicle Model Using Bond Graph and Lagrangian Technique|
|Technical Paper||A Passive Nonlinear Damping Design for a Road Race Car Application|
CitationSun, 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.
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- “Ride and Vibration Data Manual,” SAE J6a Society of Automotive Engineers Warrendale, PA December 1965