Power Machinery for Hilly and Mountainous Agriculture: Research Progress and Development Trends

Agricultural production in hilly and mountainous areas is characterized by fragmented fields, frequent slope variations, narrow farm roads, and highly variable soil bearing and adhesion conditions, which impose distinctive requirements on the traction and mobility, slope stability, maneuverability, and operational adaptability of agricultural power machinery. Focusing on tractors and related power chassis, this review synthesizes research conducted in China and elsewhere from two complementary perspectives: equipment configurations and key terrain-adaptive technologies. Research progress is reviewed for wheeled tractors, crawler tractors, slope-leveling and other special-configuration tractors, micro-tillers, and lightweight power platforms, with particular emphasis on lightweight and overall structural design, traction and machine–soil interaction, slope stability and attitude adjustment, high-maneuverability steering, powertrain and transmission systems, and intelligent operation control. The reviewed studies indicate a transition from compact, low-center-of-gravity, and fixed-configuration designs toward active leveling, continuously variable transmission, multimode steering, vehicle-implement coordination, and intelligent autonomous operation. However, pronounced trade-offs remain between lightweight design and traction capacity, high maneuverability and slope stability, and high terrain mobility and low soil disturbance. The reliability, economic viability, and long-term performance of many specialized machines under complex operating conditions also require further validation. Based on the reviewed evidence, the evolution of terrain adaptation is summarized into three stages: passive terrain adaptation, coordinated terrain adaptation, and active terrain adaptation. Future research should focus on lightweight and reconfigurable design, active slope stabilization, efficient power transmission, autonomous operation in complex terrain, and machine–soil–crop coordination, thereby advancing power machinery from fixed-structure adaptation toward multisystem coordination and ultimately perception-driven active adaptation.