Design and performance analysis of Fuzzy LQR; Fuzzy PID and LQR controller for active suspension system using 3 Degree of Freedom quarter car model

Abstract

The aim of this research work is to design three types of active controller for active suspension system. A 3 Degree of Freedom (DOF) quarter car model is used to analyze and compare the performance characteristics of the active system with the uncontrolled system or passive suspension system. Suspension system plays an essential role in isolating vehicle body from road shocks and vibrations. The goal of suspension system is to improve ride comfort; road handling and stability of vehicles. The objective is to determine control strategy to deliver better performance with respect to seat velocity; suspension deflection; sprung mass displacement; sprung mass velocity; peak overshoot; settling time etc. The three controllers designed are LQR based fuzzy controller; Fuzzy PID controller and Linear Quadratic Controller (LQR). In this work; MATLAB/SIMULINK software is used for simulation purpose and simulation result shows that active suspension system exhibits better result than passive suspension system. Also the result of comparison shows that Fuzzy LQR controller based active suspension system gives better result and stability as compared to other active controllers and passive model.