Attitude stability control for 6WID unmanned ground vehicle during steering: A collaborative controller considering minimizing tire slip energy loss

The instability of vehicle attitude and wheel slippage during turning on complex roads are key factors affecting the operational efficiency and accuracy of a variable wheelbase six-wheel independent drive unmanned ground vehicle (6WID UGV), posing a serious threat to driving safety. This article proposes a hierarchical coordinated controller to improve the attitude stability of a 6WID UGV equipped with interconnected active hydro pneumatic suspension (IAHPS) and reduce tire slip energy loss. Firstly, an integral sliding mode controller with adaptive high-order coupling factor (AHOCF-ISMC) is designed to determine the active anti roll torque required for stable roll attitude. An adaptive high-order coupling factor is introduced in the controller framework to couple physical components with different properties, avoiding overshoot and oscillation caused by integral saturation of the controller. Secondly, based on satisfying the stability of the roll attitude, the lateral stability and longitudinal traction characteristics of the vehicle are constrained and controlled. An optimization function was established to minimize tire slip energy loss within the feasible range of wheel torque determined by lateral and longitudinal control objectives. Thirdly, the particle swarm optimization algorithm was improved (IPSO) by designing adaptive weighting factors and learning factors, and is used to optimize the wheel torque distribution scheme under composite constraint conditions. Finally, the effectiveness of the coordinated controller was tested and validated in different scenarios. The results show that the designed controller has good control performance and robustness without the need to establish an accurate mathematical model, and performs well in terms of economic benefits and application prospects.