Proposal of an optimal LQR controller for the active suspension system

Abstract

Nowaday, active suspension system is widely used in the automotive industry in order to improve both ride comfort and road holding criteria. This paper focuses on applying the Linear Quadratic Regulator (LQR) control method to the active suspension system using an half roll car model. By cleverly transforming the performance index J and the state vector x, it is possible to design a controller that meets the goals of a controlled suspension system. The three LQR controllers have been synthesized, in which the first controller is focusing on the road holding criteria, meanwhile the second and third controllers on the ride comfort criteria. Simulation results in the frequency domain show that by varying the values of the weighting parameters, these three controllers will play different roles in improving the quality of the car's vibration.