Modeling and analysis of center-steering characteristics of variable-configuration wheel-track unmanned ground vehicle based on dynamic resistance

The variable-configuration wheel-track unmanned ground vehicle (VCWT-UGV) has both fast-moving speed on structured roads and strong passing ability on even roads. Steering dynamics analysis is the theoretical basis to ensure that the UGV can still maintain high maneuverability in complex environments. Based on the elastic-plastic deformation characteristics of the soil on the soft road, considering the dynamic changes in resistance and resistance torque caused by soil accumulation on the wheel side during the center-steering process of UGV. Firstly, MBD-EDM co-simulation is conducted to qualitatively analyze the characteristics of soil accumulation on the wheel side during the steering process. Then, based on the terramechanics characteristics of the locomotion mechanism, the kinematic characteristics of the UGV during center-steering are analyzed, and the mathematical model of soil accumulation on the wheel side is established. Furthermore, the dynamic model of the vehicle center-steering with lateral resistance changes is established, and the accuracy of the model is validated through tests. Based on a validated theoretical model, the changes in resistance, resistance torque, and power during the steering process are analyzed. Based on the analysis results, by adjusting the wheel deflection angle, the driving configuration and the motion modes of VCWT-UGV, the steering power efficiency of VCWT-UGV can reach 71.67%. The research results provide a valuable reference for the lateral dynamic modeling of general UGVs on unstructured roads.