An analytical study of the performance indices of air spring suspensions over the passive suspension

Abstract

In terms of vehicle dynamics aspects, the suspension system should maintain good ride quality and road holding performance against the road irregularities especially in the case of high driving speeds. In this paper, two different air spring models (classic air spring; dynamic air spring model) are presented. Thereafter, both the dynamic air spring suspension and the passive suspension are compared in terms of RMS of body acceleration, suspension travel, and dynamic tire force. Based on that, a 2-DOF quarter mathematical model is implemented in MATLAB/Simulink platform. The ride quality and road handling responses are evaluated considering a vehicle speed of 20 m/s and road Class C. Besides, a parametric analysis is conducted to investigate the influences of the air spring model parameters on the vehicle dynamics. Then, the results are analyzed and compared for both the classic and dynamic air spring models showing the improvements over the passive suspensions. Furthermore, time domain and frequency domain analysis are then presented for the proposed suspensions. The obtained results indicated that, for the dynamic air spring model, the body acceleration, suspension travel and dynamic tire load improved by 27%, 10%, and 20%, respectively, which provides more comfort and easy handling performances comparing to the passive suspension. Keywords: Air spring, Quarter suspension model, Ride comfort, Road holding, Commercial vehicles