Optimization And Research Of A Light Off-road Vehicle Suspension Parameters Based On Ride Comfort

With the development of economic society and the improvement of living standards,the car is no more a simple means of traffic,people have a higher demand for the comfort of its driving.O n the off-road vehicle,people pay more and more attention to its ride comfort.The suspension is a kind of transfer device between wheel and body.The performance of the suspension is t he most important and the most direct factor to affect the ride comfort of the vehicle.So it is very important to study the optimization design of the suspension system and improve the ride comfort of the off-road vehicle.In order to improve the ride comfort of a light off-road vehicle,the suspension system of the vehicle was optimized.The concrete research content of this article are as follows:Firstly,this paper introduced the structure of suspension system and analyzed the ride comfort diagram.According to the performance requirements of both suspension design and suspension components,the suspension stiffness and shock absorber damping were chosen as the design parameters of the suspension system.Then,according to the needs of the research on r ide comfort,the seven degree of freedom vehicle model was established,and the dynamic equations were obtained by the Lagrange method.The accuracy of the model were verified by the national standard on road test.The random road inputs were generated by the harmonic superposition method,and the verification was carried out with the standard pavement.The NEWMARK-? method were used to solve the vibration differential equation of vehicle system.For ride comfort,random input simulation were carried out at different speeds.The evaluation for ride comfort was carried out on class B road.Finally,the optimal Latin hypercube method was used to do the DO E,analyzing and the influence of suspension stiffness and damping on the response output.According to the DO E results,the design variables and the suspension system output's approximation model were built by response surface,RBF neural network and Kriging respectively.Coefficient of determination was used to test fitting accuracy,and Kriging approximation model fitted the best.So multi-objective particle swarm optimization algorithm was applied to do the optimization design of the suspension system parameters based on Kriging approximation model,using rms.value of weighted body acceleratio n,the suspension dynamic deflection and dynamic tyre load as optimization objectives.The optimized results showed that the average reduction of rms.value of weighted body acceleration was 8% at different speeds,the probability of the impact limit of the suspension was also reduced to a reasonable range,proved that the ride comfort of the light off-road vehicle was improved well by the suspension optimization design.