Optimization Design Of Double Wishbone Independent Suspension Of Car And Study Of Vehicle Stable Steering Characteristic

Automobile suspension system is one of the most pivotal subsystem that affects vehicle’s dynamic performances, and the automobile wheel alignment parameters that decided by suspension guiding mechanism has a direct effect to vehicle’s handling stability. Therefore, the research has important theory value and actual significance to the design of automobile suspension system and the study of vehicle performance.Double wishbone independent suspension system of a car made in China is taken as study subject in this thesis, the main research work are studied as follows:At first, aiming to the spatial structure of double wishbone independent suspension, the formula of the key points’coordinates are deduced based on spatial analytic geometry theory, and the mathematical model of kinematics characteristics are given. The suspension kinematics characteristic curves are obtained by MATLAB software, and the available automobile suspension design theory knowledge and predecessor’s experience are used to analyze these characteristic curves, finding that some kinematic characteristic parameters don’t meet the design requirements. Based on ADAMS suspension simulation model is set up, which is used to run kinematics analysis, the accuracy and the reliability has been confirmed with the given mathematical model by analyzing simulation result.Then, a method of suspension optimization design based on the theory of spatial mechanisms adaptive fitting kinetic synthesis is put forward. From the perspective of improving the original suspension kinematics property, this paper optimizes the structure of the original suspension, as a result, the suspension kinematics property is clearly improved after optimization by analyzing before and after optimized kinematic characteristics curves. The optimized suspension model is built based on ADAMS/Car, which is used to run dynamic simulation, and roll parameter curves of the optimized suspension are obtained, and the roll characteristics parameters of the optimized suspension meet the design requirements by analyzing these curves.At last, on the basis of the established optimized suspension model, the rear suspension system, the power-train system, the steering system, the body system and the tire system are established in ADAMS/Car, by adjusting the model until the whole vehicle dynamics model has been completed. The established whole vehicle model is run to stable steering simulation experiment, the result shows that the whole vehicle has a good stable steering characteristic.The effective method is provided to solve the structural design and improvement of the suspension system in this thesis, and the study has certain reference value for improving the handling and stability of suspension system and vehicle performance.