Mini-vehicle Suspension System Design And Vehicle Ride Comfort

Suspensions connect wheels or axles to body or chassis elastically, and are important systems in vehicle. The job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to ensure the comfort of the passengers.This dissertation concentrates primarily on the impact of suspension parameters on ride comfort. It covers determining the parameters of the full vehicle, finding out best parameters of suspension from mathematical models, designing overall suspension systems preliminarily, building full vehicle model and evaluating performance of ride. This paper contains the following sections:In layout phase, we choose the proper drive type of the vehicle, determine the parameters and predict the performance of the vehicle. Finally complete the overall layout design, and draw a layout sketch.Based on analytical models built from a number of ordinary differential equations, the impact of suspension parameters, such as stiffness of suspensions and damping ratio of shock absorbers, on vehicle ride comfort is studied, to determine the most suitable parameters. The results are displayed graphically.According to relevant information, the front suspension construction of prototypes is designed, and the dynamic model is built thereby. Then the suspension is optimized base on the solutions obtained from simulations.In the phase of rear suspension design, an asymmetric leaf spring is defined firstly. Then the vary-stiffness-leaf-spring is designed. The stiffness characteristics of leaf spring are analyzed and verified resort to the Finite Element Method.Finally, the synthetic multibody model of full vehicle is established, and implemented in the four-poster test rig in ADAMS/CAR, responses of the body is abstracted as inputs to the person-chair systems. While the solution is obtained, ride comfort performance is computed.