Robust and Optimal Control Design for Vehicle Suspension System

Abstract

Developing a reliable control algorithm for a mechatronic suspension can be tricky because of the nonlinear nature of the system and the necessity to achieve a good trade-off between the requirements of road handling ability and the comfort of passengers. This paper assesses the performance of two control methods, the H-Infinity (H ∞) and linear quadratic regulator (LQR), applied to an active suspension system. This suspension system uses sensors and actuators in addition to the springs and dampers of the traditional suspension system. It combines software, electrical, and mechanical parts to improve the car handling and convenience of passengers on the road. A quarterly car automotive suspension model consisting of 2 degrees of freedom (2 DOF) is proposed as the case study. The suspension deviation, wheel displacement, and upward acceleration of the car frame are the performance parameters considered in this research. The aim is to strike a perfect balance while achieving minimum readings of car chassis acceleration and wheel deflection demonstrated by each controller when steady state error approaches zero from the suspension response. The body acceleration and wheel deflection affect the passenger comfort and road handling, respectively. Time-based simulation is carried out in MATLAB/Simulink environment to verify the effectiveness of the proposed control mechanisms. The results of the simulation demonstrate the effectiveness and robustness of the proposed control schemes.