| With the development of automobile technology and the increase of automobile usage,the corresponding higher requirements have been put on automobile performance.Handling stability and ride comfort are two important performances of automobile system,which affect and contradict each other.In previous researches,they were usually optimized separately,which makes it difficult to achieve the optimal comprehensive performance of automobile.To solve above problems,this paper take air suspension vehicle systems as the research object,in order to give attention to both the riding comfort and handling stability balance optimization,the collaborative optimization method is used on the internal relations of mutual coupling between the two performance,to realize the optimization of handling stability and riding comfort,eventually making the automobile comprehensive performance optimal.The main contents of this paper are as follows:(1)Based on the influence of air suspension system on automobile performance,the characteristics of air suspension are analyzed.The ideal elastic characteristic curve of the air suspension system under full load conditions is fitted by fitting formula.According to the static balance position stiffness of the suspension system and the suspension stiffness at the vertex when the upper and lower jumps,the actual suspension elasticity characteristic curve can be obtained.According to the relationship between suspension and air spring position,the air spring stiffness is calculated,and the damping coefficient of the shock absorber is calculated,which lays the foundation for the modeling simulation of the whole vehicle.(2)Based on the multibody dynamics software ADAMS to establish the automotive dynamics model,the actual research model of this paper as an example to modify the vehicle model parameters,the air spring stiffness and damping coefficient obtained above applied to the suspension model.In order to verify the accuracy of the model,the two-wheel edg simulation test of the front and rear suspensions is carried out,and the test evaluation index is analyzed.With reference to the test method of manipulating stability and smooth driving in the national standard,the simulation test is carried out in ADAMS,and the evaluation index is scored according to the scoring formula in the national standard,and the analysis shows that both performance needs to be optimized and difficult to balance,so the method of coordination optimization is used to optimize.(3)Taking the mechanical characteristics parameters of the air suspension as design variables,the response surface method was used in ADAMS/Insight module to establish an approximate model of ride comfort and handling stability.ISIGHT was used as the optimization platform,and a solution model was established in ISIGHT based on the theory of collaborative optimization.The optimal solution of the model and the optimal value of the corresponding variable were obtained.After the optimization,the air spring stiffness and damping coefficient of the front and rear suspension were re-set into the vehicle model,and the simulation was carried out according to the simulation test method of control stability and ride comfort,and then compared with the two performance evaluation indexes before the optimization.The results show that the comprehensive score of the steady-state rotary test of vehicle handling stability is increased by 4.3%,the comprehensive score of the steering back to positive test is increased by 0.9%,the comprehensive score of the snake test is increased by 7.4%,and the comprehensive score of the random road surface input in the ride comfort simulation test of 60km/h and 80km/h was increased by 6.8% and 1.27%.The comprehensive score of pulse input simulation test under the speed of 30km/h to80km/h was increased by 8.7%,14.3%,9.7%,8.7%,6.5% and 14.3%,respectively.Therefore,the coordinated optimization method can optimize the vehicle’s handling stability and ride comfort. |
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