Optimum Design Of Air Spring With Volume-Variable Auxiliary Chamber Based On Genetic Algorithm

Car suspension is necessary to have elastic components to buffer the car vibration;also have damping the original consumption of vibration energy,attenuation amplitude.The air spring itself can only play the role of elastic components,if you rely on an external damper to form a suspension,will increase the cost of the suspension space and economic costs.Thus,an air suspension is created by adding an auxiliary chamber to produce a damping effect.With regard to the structure of the variable volume auxiliary chamber,many programs have been designed.Honeycomb structure,too many ports,so that the number of control components too much,resulting in complex structure,high control costs,and difficult to ensure that the seal;single piston-type auxiliary chamber,in the process of moving the piston will make the two sides,Resulting in a significant decline in the overall system stiffness.Based on this,the subject of the design of a volume can be fast,continuous change and constant internal pressure chamber is particularly important.Based on the research results of domestic and foreign research,based on the engineering thermodynamics and aerodynamics theory,the simulation model of air spring system with auxiliary chamber is established in Matlab / Simulink environment.Through the static test and the dynamic test,the mechanical characteristics of the air spring with volume-variable auxiliary chamber are summarized,and the correctness of the simulation model is verified.Finally,the multi-objective optimization design model of the suspension system is constructed according to the optimal design theory.The genetic algorithm is used to optimize the auxiliary chamber volume and the damping coefficient of the shock absorber under typical operating conditions.After the optimization of multiple targets with the parameters of the air suspension system with additional gas chamber,a set of parameters were randomly selected for simulation test.The results show that the root mean square value of the dynamic load of the tire increases by 6.0% The mean square value of the mass acceleration is reduced by 14.5% and the rms value of the suspension moving stroke is reduced by 13.4%.According to the weight of each index,it can be seen that the increase of the dynamic load of the tire causes the grounding performance of the vehicle Somewhat worse,but the overall smoothness of the vehicle performance has been significantly improved.To sum up,the optimization of two control parameters for the additional gas chamber volume and the connecting pipe diameter of the suspension system can reduce the number of gears to be adjusted and effectively improve the ride comfort of the vehicle.It provides technical support and theoretical guidance for the application of variable attachment air spring.