Dynamic modelling and stability analysis of the articulated tracked vehicle considering transient track-terrain interaction

Articulated tracked vehicles (ATVs) exhibit enhanced steerability but reduced yaw stability. Apart from the track-terrain contact, the dynamics of the articulated frame steering (AFS) system strongly influences the stability of ATVs. We developed a detailed hydraulic steering system and a yaw-plane ATVs model for vehicle stability research. The transient characteristic of track-ground contact was considered. The multibody dynamics model by Recurdyn/Track software was compared with the established model to verify the model correctness at time-domain and frequency-domain. The result suggests that the vehicle yaw stability can be evaluated in terms of the oscillation frequency, damping ratio, overshoot, and steady-state deviation of articulation angle response. A multi-objective optimization is proposed to obtain the optimized structural parameters of AFS system by employing response surface method (RSM) and non-dominated sorting genetic algorithm II (NSGA-II). The optimal solutions revealed that more compact mechanism design of AFS system contributes to a compromise stability performance with 4.44 % decrease in the oscillation frequency and 10.3 % decrease in the damping ratio.