Investigation of tracked mining vehicles' driving performance at varying travel speeds by experimental and numerical simulation

The design of a tracked mining vehicle (TMV) that can efficiently and safely travel on the deep seabed is the core technology in the deep-sea polymetallic nodule mining system, and one of the main aspects influencing the TMV's driving performance and efficiency is its travel speed. To overcome the current limitations of low mining vehicle efficiency and susceptibility to slipping and sinking, this study investigates the impact of travel speed on vehicle performance based on laboratory model experiments and numerical simulation methods. Initially, track driving model experiments were conducted, revealing that traction force increases with travel speed, analyzing the influence on the stage-wise variation of shear strength-displacement relationship between the track and sediment interface. An optimized traction force calculation model was proposed, and applied in multi-body dynamics software and validating its rationality. Multi-body dynamics simulation experiment results indicate a significant increase in the settlement amount of TMVs with increasing travel speed. However, the magnitude of the travel speed changes the variation pattern of settlement amount with travel displacement, and it was found that the slip rate during stable vehicle traveling is positively correlated with travel speed. The impact of travel speed on the performance of TMVs traveling on sediment eroded by jets in actual engineering was also analyzed. It is found that excessive or insufficient travel speed is detrimental to the performance of TMVs. In this study, when the travel speed is 0.7 m/s, the effect of weakening the mechanical strength of eroded sediment on TMV's driving performance is relatively small. This research provides a scientific theoretical basis for improving mining vehicle efficiency and enhancing mining capability.