| With the rapid development of China’s economy,the number of semi-trailer liquid tank truck which can carry liquid goods is increasing year by year.Under emergency braking,emergency steering or avoidance conditions,the liquid in the tank is forced to shake violently,resulting in sloshing force and acting torque on the tank wall,affecting the handling stability,and even leading to serious road traffic accidents such as rear-end collision and rollover.Taking the semi-trailer liquid tank truck as the research object,this paper analyzed the influence of liquid sloshing in the tank on the vehicle handling and stability under the working conditions of emergency braking and emergency steering.Based on the analysis results,the control strategy of semi-mounted liquid tank truck handling stability(anti-rollover)under dangerous conditions was designed.The specific work was as follows:First,based on the fluid simulation software FLUENT,a two-way fluid-solid coupling analysis was carried out on the liquid tank and the liquid in the tank,and the force and moment of the liquid sloshing on the tank were obtained.Based on Ansys Workbench,the tank structure model and fluid model were established respectively,and the two-way fluid-structure interaction simulation analysis was carried out through mesh division and boundary condition setting,so as to obtain the liquid sloshing and liquid impact force law in the tank under emergency braking and emergency steering dangerous conditions.Secondly,based on the results of two-way fluid structure coupling,the influence of liquid sloshing in the tank on vehicle handling and stability under dangerous working conditions was simulated and analyzed by using Matlab and TruckSim software.The vehicle dynamics model of the semi-trailer liquid tank truck and the semi-trailer vehicle model of the equivalent rigid cargo were built respectively by TruckSim software,and the influence of the liquid sloshing in the tank on the vehicle handling stability was compared and analyzed by joint simulation.According to the analysis,the liquid sloshing in the tank affects the braking distance and driving direction stability of the vehicle in emergency braking condition,and the liquid filling ratio in the tank should avoid the range of 60%-80% as far as possible.In the emergency steering condition,lateral force of the tank body affects the roll stability of the vehicle.Under the condition of angular step,the liquid filling ratio in the tank is 90%,and the vehicle is prone to rollover when the vehicle speed is 47 km / h.Finally,the handling stability(anti rollover)controller of semi-trailer liquid tank truck based on differential braking was built by using Matlab / Simulink software.Based on the TTR and LTR parameters of the vehicle,the anti-roll early warning system was established.The fuzzy PID control algorithm was used to output the additional yaw moment,and the differential braking control was used to distribute the brake pressure of the brake wheel cylinder to implement anti-roll control.Through the verification of angular step condition and high attachment fishhook condition,this strategy can effectively prevent the vehicle from rollover and improve the handling stability and driving safety of the vehicle.It has a certain reference value for the research of semi-trailer liquid tank truck active safety control technology. |
PDF Full Text Request