Suspension system is an essential part of vehicles that has an important role in the quality of driving, ride comfort, and safety of vehicles. Passive suspension systems do not provide a proper ride comfort against all of the road’s profile input. Hence, in order to improve the ride comfort, active systems are used. The aim of this paper is modelling of active and passive systems of vehicles using Bond Graph method and designing the LQR controller for it. In this paper a quadratic vehicle model has been used to design the controller. However, this controller has been applied to the full vehicle model. The quarter vehicle model has 2 degrees of freedom: sprung mass’ movement and unsprung mass’ movement. The 7 degrees of freedom vehicle model contains role, pitch, and yaw angels, as well as the two abovementioned. In order to model the active suspension system 20-sim software has been used. In addition, MATLAB Software has been used for designing the controller. The results of active suspension system show the improved ride comfort than without a controller.
Keywords: full vehicle model, Bond Graph method, active suspension system, optimal controller design