Active Suspension System In Automobiles

Abstract

This report is aimed to study active suspension system in automobiles and provides a ground work for modeling of an active and passive suspension systems. The design of a suspension system for a vehicle involves two conflicting requirements. Increasing passenger comfort requires that the suspension system of the vehicle be soft whereas good handling of the vehicle requires that the suspension system be hard. A conventional passive system is designed by arriving at a compromise between these conflicting requirements. An active suspension system addresses this trade off better than a conventional passive suspension. Various types of mathematical models (Quarter Car & Half Car Model) that are used for suspension modeling is carried out in this project work. H-Infinity controller is used to analyze the quarter car model. Applying Linear Quadratic Regulator (LQR) and Front Rear Preview Controller as control strategies, simulations were run for a half car model along with there results in SIMULINK/MATLAB enviornment. On comparing the performances active suspension is proved better than a conventional passive system in terms of ride comfort, and preview controller is better than LQR in terms of providing both ride comfort and stability to the vehicle.