Research On Comfort Of Vehicle And Optimization Of Suspension System

Ride comfort is one important index of the high-speed and efficient vehicle, it influents not only the comforance of passengers, but also the psychology. It plays a important role in ensuring a good mentality, accurate and sensitive response of the driver in a complex driving conditions, so people have paid more and more attention on it. But the traditional analysis can't satisfy the demand, as a new technology, virtual prototyping technology has been widely used in vertical dynamics. This is a discussion of suspension system ride based on the dynamics software ADAMS.Firstly, we summarized the developments of the ride comfort research. Then we dissussed the criteria and methods of ride evaluation and the theory of optimal design.This paper extracted the parameters of some vehicle and analyzes the dynamics model of the vehicle with multi-object dynamics software-ADAMS, including leaf spring suspension or air spring, tires and other systems, it streamlines the body and seat. The paper not only prepared the road file for ADAMS/View based on the superpositon principle and the data of test, but also verified the correctness of the pavement model according to the displacement power spectral density. On the foundation, we conclued the solving time-domain simulation in the random input excitation. The analysis deal with the vibration results of vehicle with the leaf spring or the air spring in the vertical direction when the car was riding on B class road in 30km/h. We evaluated the ride performance according to the standards and compared it with the test result to verify the validity of the model. The result proved that the leaf spring could not fulfill the effect of air spring. We recalculated the spring parameters on the base of the spring design theory and replaced the leaf spring with spiral spring. According to the optimization criteria, we minimized the root mean square of vertical acceleration as the objective function, using dynamic deflection, static deflection and stiffness matching as constraints to optimize the stiffness of leaf spring. It proved that the ride comfort improved effectively. The leaf spring was choosed as the more reasonable and more competitive spring than the air spring. Finally, we reverse to calculate the size of leaf spring according to the optimization. The result optimize the ride comfort, and reduced vehicle weight and the cost of production.