Research On Vehicle Rollover Stability Based On Suspension's Stiffness And Damping Optimization

According to statistics,heavy vehicle rollover accident causes great losses and hazards,which is only inferior to the frontal crash.Even if the occupant of the car is wearing a seat belt,there is still a 75% chance of death.The rollover accident not o nly results in the loss of the life and property of the occupants in the car,but also causes secondary traffic accidents,which seriously restricts the development of the transportation industry in China.In order to reduce the risk of rollover of heavy vehicles,the sensitivity of vehicle parameters to rollover was analyzed with the vehicle loading on the 10~15t without side wind influence,and the adjustable suspension stiffness and suspension damping were studied.An anti-rollover method based on the stiffness and damping parameters of the suspension is proposed.The method not only ensures the riding comfort,but also improves the ability of anti-rollover of the vehicle to resist rollover.The research content mainly includes the following aspects:First,the principle of vehicle rollover is illustrated by combining the mechanism of vehicle side tilting and the stability mechanism of transverse pendulum,and a three-degree of freedom of vehicle dynamic model that can be applied to rollover research is established.In order to avoid ignoring the errors caused by the side bias of the tire,a tire model based on magic formula is established and a simulation model is built in Simulink.At the same time,the Simulink's simulation results of various typical working conditions are compared with the results of TruckSim to verify the accuracy and effectiveness of the model.Then,A three degree of freedom dynamic model which can correctly reflect vehicle's roll motion,yaw motion and lateral motion characteristics is established,which is suitable for vehicle rollover research.In order to avoid the error caused by neglecting the side bias of the tire,a tire model based on magic formula is established,and the rollover principle of the vehicle was described in conjunction with the roll stabilizing mechanism.Then the vehicle simulation model is built in Simulink,and a variety of typical working conditions are selected for simulation.In order to verify the correctness and effectiveness of the three degree of freedom model,the simulation results are compared with the TruckSim results set by the same parameters.Finally,the sensitivity of parameters in rollover evaluation index is analyzed.It is further proved that optimization of suspension stiffness and damping can enhance vehicle anti rollover capability.Multi Island genetic algorithm is combined to optimize the stiffness and damping characteristics of the suspension when the front wheel reaches the maximum angle under different working conditions and the vehicle does not turn over.The optimized stiffness damping characteristics can meet the comfort and comfort of the suspension and meet the stability requirements of the side rollover.The simulation results show that the vehicle with improved suspension characteristics obviously improves vehicle rollover stability.Therefore,the proposed method based on optimization of suspension stiffness and damping to enhance vehicle anti rollover capability has practical engineering significance and practical value in practical engineering.