Multibody model for enhancing the dynamic behavior of an agricultural tractor

A numerical model of the front axle suspension of a medium-range agricultural tractor is presented. The final goal is developing a numerical tool with real-time capabilities for possibly improving the dynamic response of the vehicle. The model consists of a multibody model for simulating the dynamics of the complete tractor and a hydraulic model of the suspension actuation system, integrated in Simulink environment. The models run in co-simulation, driven by the input signals commanding the valves of the hydraulic cylinder, in a closed-loop system. Model validation has been carried out by using experimental data obtained from a test referred to as leveling maneuver, where the suspension displacement has been measured in addition to the cylinder controlling signals (normally available on board). The validated model proved quite accurate and reliable in predicting the dynamic behavior of the tractor during the tested maneuver. Further investigations are ongoing to achieve real-time compliance, as well as to verify the model performance in different operating conditions.