Modeling and Analysis of Passive Suspension System Using Half Car Model Based on Hybrid Shock Absorber Model

Abstract

The vehicle suspension system has been a focus of attention to researchers over a long period of time as it improves vehicle stability, handling properties and rode comfort to the passengers. This paper presents modelling and comparative analysis for the passive suspension using linear model (constant damping coefficient) and hybrid shock absorber model. A shock absorber is the vital element of the suspension system and typically characterized by the force-velocity curve which is hysteresis and nonlinear in behaviour. Most of researchers used linear constant damping coefficient to analyze the vehicle performance characteristics. In this work a nonlinear hybrid shock absorber model from established literature is used to analyze the vehicle performances. To developed the hybrid shock absorber model, author used experimental shock absorber damping forces to devise two different models, namely, piecewise linear model and hysteresis model. The hybrid shock absorber model is incorporated into half car suspension system to investigate the influence of damping forces on the response characteristics of a vehicle. The simulated results generated by using hybrid model are compared with linear model and also with the existing published results. The modeling and simulation is carried out by using Simulink for bump road perturbation. The simulation results show that the performance characteristics of vehicle suspension using hybrid shock absorber model improves the road comfort of the passengers. Results corresponding to body displacement, body acceleration and pitch of the vehicle are furnished. It can be concluded that the linear damper model is inadequate to capture the vehicle performance accurately due to the absence of hysteresis force. Hence, to understand and study the performance of the vehicle the hybrid shock absorber model is essential.