Modeling and Simulation of Quarter Car Semi Active Suspension System Using LQR Controller

In this paper design of the Linear Quadratic Regulator (LQR) for Quarter car semi active suspension system has been done. Current automobile suspension systems use passive components only by utilizing spring and damping coefficient with fixed rates. The vehicle suspension systems are typically rated by its ability to provide good road handling and improve passenger comfort. In order to improve comfort and ride quality of a vehicle, four parameters are needed to be acknowledged. Those four parameters are sprung mass acceleration, sprung mass displacement, unsprung displacement and suspension deflection. This paper uses a new approach in designing the suspension system which is semi-active suspension. Here, the hydraulic damper is replaced by a magneto-rheological damper and a controller is developed for controlling the damping force of the suspension system. The semi-active suspension with controller reduces the sprung mass acceleration and displacement hence improving the passengers comfort.