Adaptive balance control strategy for four-wheeled unmanned ground vehicle

When operating in complex, unstructured terrains, the attitude instability of unmanned ground vehicles under lateral disturbances significantly limits their obstacle-crossing capability and operational safety. Addressing this issue in a four-wheeled unmanned vehicle equipped with a novel longitudinal-transverse arm independent suspension structure, this paper proposes an adaptive hierarchical control strategy based on vehicle attitude feedback. First, a geometric model for slope stability was developed using the innovative suspension configuration, revealing the physical mechanism whereby adjusting vertical height differences in the suspension actively suppresses roll motion and enhances rollover resistance. To mitigate attitude instability in perception blind zones, an adaptive hierarchical control scheme was proposed: the upper layer employs precise kinematic inversion to map real-time roll angles into actuator feedforward compensation parameters for rapid response; the lower layer utilizes a gain-scheduled PID algorithm that performs nonlinear adaptive adjustments based on roll amplitude variations, dynamically optimizing anti-roll control. Joint simulations using ADAMS and MATLAB/Simulink demonstrated that this strategy reduces roll angle fluctuations on uneven slopes and continuous rough surfaces. Physical prototype tests confirmed that the longitudinal-transverse arm suspension design combined with the adaptive hierarchical control strategy significantly improves lateral stability and overall obstacle-crossing performance of unmanned vehicles in complex unstructured environments.