Sensitivity analysis and prediction method for steering capability of skid-steering vehicles coupled with hydrostatic propulsion system

Skid-steering vehicles (SSVs) are widely used, and clarifying the impact of the propulsion system on steering capability is crucial for improving performance. SSVs with hydrostatic propulsion systems (HPS) steer by building up pressure to overcome resistance, making pressure a key factor. However, the strong coupling between HPS and vehicle dynamics complicates the analysis of steering pressure. To address this, this article establishes a coupling model between HPS and vehicle dynamics and analyzes the dynamic reaction of HPS during steering. Global sensitivity analysis (GSA) then identifies the main parameters affecting pressure characteristics. Based on these results, a method for predicting steering capability is proposed. The model's accuracy, parameter influence, and the effectiveness of the prediction method are verified through vehicle tests. Results demonstrate the model accurately reflects the interaction between motion state and HPS response. Vehicle speed is a key factor influencing pressure overshoot, which rises substantially with increased speed. Considering pressure overshoot enables accurate prediction of steering capability. This study provides a theoretical foundation and application support for forward design and control of SSVs.