Prediction of Tractor Traction Performance and Traction Efficiency in Hilly and Mountainous Terrain

To address the difficulty of existing tractor traction performance models in accurately characterizing the influence of slope in hilly and mountainous terrains, a hierarchical prediction framework for tractor traction performance was established based on wheel–soil interaction mechanics. By introducing the soil cone index and integrating the tire index and mobility index, a soil–tire driving model incorporating slope effects was developed. Furthermore, a tire load model considering slope-induced axle load redistribution was established to describe the variation in normal loads on the front and rear axles during uphill travel. At the vehicle level, slip efficiency and rolling efficiency sub-models were formulated based on the kinematic mismatch coefficient between the front and rear axles, and were coupled with transmission efficiency to develop a comprehensive traction efficiency prediction model. Simulations were carried out under slope gradients of 5%, 15%, and 25% to predict the variation trends of tractor traction performance parameters under different operating conditions. The results provide a theoretical reference for traction performance prediction and parameter matching optimization of tractors operating in hilly and mountainous terrains.