| In order to improve the ride comfort and road friendliness of heavy commercial vehicles,a lateral interconnected air suspension system with a throttle valve has been developed.The lateral interconnected air suspension can reduce the vibration of the vehicle body and the load of the tires on the ground by exchanging gas in the air springs on both sides of the axle.In this paper,a vehicle model with lateral interconnected air suspension and a four-wheel road excitation model are established,and the influence of the lateral interconnected air suspension on vehicle ride comfort and road friendliness is explored,and finally the parameters of the lateral interconnected air suspension are optimized and analyzed.The specific research work is as follows:(1)According to the structure of the lateral interconnected air spring,it is divided into two parts,the air spring airbag chamber and the interconnecting pipe.Based on the related theories of thermodynamics and fluid mechanics,two non-linear mathematical models are established respectively.The dynamic and static stiffness experiments of the interconnected air spring were designed and carried out.The simulation results of the interconnected air spring model and the experimental results were compared and analyzed,and the accuracy of the interconnected air spring model was verified.(2)The commercial vehicle is simplified into a ten-degree-of-freedom vehicle model,and the mathematical model of the vehicle is established based on the dynamics from the three modules of the cab,body,and chassis.Based on the white noise filtering method,the vehicle four-wheel random road time-domain excitation model is established,and this is used as the displacement input excitation of the vehicle model.Combining the interconnected air spring model and the ten-degree-of-freedom vehicle model,a lateral interconnected air suspension vehicle model is established,and time-domain simulation analysis is carried out.The simulation results are verified by real vehicle experiments.(3)Taking the lateral interconnected air suspension vehicle model as the research object,the ride comfort index and road friendliness index obtained by simulation are taken as the objective function of multi-objective optimization,and the influence of interconnected air suspension parameters on the evaluation index is explored.Taking the inner diameter of the throttle valve and the initial control height of the interconnected air suspension as the optimized design variables,the road roughness,driving speed,and vehicle load are regarded as interval uncertain parameters,and a multi-objective uncertain optimization problem model is established.Using the Legendre interval analysis method proposed in this paper,the uncertain optimization problem is transformed into a definite optimization problem.(4)Under the two working conditions of good road conditions and bumpy road conditions,the multi-objective particle swarm algorithm is used to obtain their respective Pareto optimized solution sets,and the maximum improvement method is used to select the optimized solution with the greatest improvement from the Pareto solution set as the final solution.Finally,the optimization results are analyzed to verify that the optimized lateral interconnected air suspension can make the vehicle have good driving comfort and road friendliness under different sizes of road roughness,driving speed,and load. |
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