In order to prevent the rollover risk of four-axle heavy dump trucks during lifting and unloading, encountering significant road cross slope angle or uneven load distribution, a comprehensive dynamics model for the lifting and unloading on the slope was established. This model consisted of the roll dynamics model, the electrohydraulic servo actuator model, the lifting kinematics model, and the cargo sliding kinematics model. A rollover evaluation index of the energy method was proposed to assess the rollover risk during lifting and unloading. The correctness of the model and the feasibility of the energy method were verified through MATLAB/Simulink simulations. Then, a hierarchical anti-rollover control strategy was designed, and a backstepping sliding mode controller based on the snow ablation optimizer was employed as the upper-level controller to generate the desired force for active suspension actuators, while the proportional integral control served as a bottom controller to track the desired force accurately. The simulation results show that, compared to the no control and backstepping sliding mode control, the roll angles of cargo and cargo box were reduced by 23.70% and 2.28% under a significant road cross slope angle condition, and reduced by 22.74% and 0.19% under a large uneven load distribution condition. The designed control strategy is more effective in preventing the risk of rollover.
Li et al. (Sun,) studied this question.