Improvement of Trucks Ride Dynamics Using a Hydraulic Semi-Active Suspension System

In this paper, a continuously controlled semi-active suspension system is designed for trucks main suspension. Using a linearized seven degrees of freedom mathematical model equipped with hydraulic and hydro-pneumatic components, the optimal damping forces for truck front and rear suspensions are designed based on optimal control theory using Linear Quadratic Regulation (LQR) to improve the ride comfort and dynamic tyre loads. The practical limitation for the damping forces and the time lag for system controllable elements are taken into account. The results are generated considering the suspension components non-linearity and the model is excited by statistically random road. The frequency domain results as power spectral density and the root mean square values are compared with those obtained from conventional passive suspension system.