Study On Handling Dynamics And Stability Of Heavy-duty Vehicles With Storage Tank

As a relatively efficient and low-cost means of transportation,heavy-duty vehicles with liquid tank occupy an irreplaceable position in the liquid cargo transportation market.However,in addition to the significant adverse factors such as heavy load,high center of mass and large volume,the liquid sloshing in the storage tank is easy to produce complex coupling effect with the vehicle body movement under extreme operating conditions such as emergency obstacle avoidance or high-speed turning,which leads to traffic accidents such as vehicle instability,sideslip or rollover,and then economic loss,environmental pollution and casualties a major accident.In the paper,taking the heavy-duty vehicle with liquid storage tank as the main research object,considering the additional moment and sloshing damping effect caused by the lateral movement of liquid mass center,the dynamic equation of liquid sloshing in the steady steering tank of heavy-duty vehicle with liquid storage tank is derived by using mathematical vector analysis method and Lagrangian equation,and the roll dynamic model of multi degree of freedom of vehicle-liquid coupling is established by using the theory mechanical analysis and vehicle theoretical knowledge,and the direct yaw moment control and active anti roll control are proposed based on the theory of sliding mode variable structure to ensure the stability of the vehicle.Among them,the specific work can be listed as follows:(1)Based on the principle of equivalence,the first-order simple pendulum model is used to equivalent the liquid sloshing in the tank and the shaking force and shaking moment are solved.The numerical model of liquid sloshing in the tank is established by using the finite element software,and the correctness of the finite element numerical model is verified.The parameters in the equivalent simple pendulum model are solved and the parameters are identified by the least square method.Finally,the validity of the equivalent simple pendulum model is verified by the verified finite element model.(2)Considering the influence of additional moment and sloshing damping caused by the lateral movement of liquid mass center,liquid sloshing in the tank is equivalent to a single sloshing model according to the principle of equivalence,and the main parameters in the model are identified.The dynamic equation of liquid sloshing in the tank is derived by using mathematical vector method and Lagrange equation.The roll dynamic model of multi degree of freedom of vehicle hydraulic coupling is established by using the theory mechanical analysis and vehicle theoretical knowledge.Comparing with the model established by Trucksim software by inputting the sinusoidal working condition,it is further verified that the model can meet the dynamic simulation requirements within the allowable error range.(3)Considering the mutual coupling of liquid sloshing in tank and vehicle body motion,the influence of liquid sloshing in tank on the handling dynamics and stability of heavy vehicle with liquid tank under the excitation of different filling ratio and lateral acceleration is analyzed in detail,and the driving stability characteristics of vehicles under two common working conditions of step steering and double shift line are further studied,so as to control the vehicle actively in the later stage,the system has laid a certain foundation.(4)In view of the multi degree of freedom nonlinear system of heavy-duty vehicle with liquid storage tank,combined with the idea and method of direct yaw moment control,the sliding mode variable structure controllers of sideslip angle and yaw rate are designed respectively.Based on the control parameters,the optimal additional moment of the vehicle is determined.Through sinusoidal input conditions,the vehicle is simulated under different speed and different adhesion coefficient road conditions.For the emergency obstacle avoidance and high-speed driving conditions,the vehicle active anti roll sliding mode controller is designed,and the stability of the vehicle in various conditions is verified through the simulation of emergency double lane shifting and high-speed driving conditions.