Research Of Dynamic Modeling For McPherson Suspension Based On Component Characteristics

As an important assembly of modern automobile, suspension system has a significant effect on the vehicle handling stability and ride comfort. In the concept development stage of vehicle development and design process, due to the lack of specific structure parameters of product, vehicle manufacturers and parts suppliers widely use the suspension model based on the assembly characteristics.As the automotive lightweight becomes an important objective of current automobile design and product development, vehicle manufacturers and assembly manufacturers propose new requirements for the suspension parts suppliers, they hope the parts not only ensuring the performance of vehicle and assembly, but also with good reliability and durability. However, suppliers cannot ensure performance, reliability and durability at the same time, because the suspension model based on assembly characteristic cannot provide accurate load and configuration of chassis key components. The suspension model of ADAMS can calculate load and configuration of the components. But because of the stiff differential algebraic equations, the model cannot achieve real-time simulation, and due to the simple rubber model, the suspension model has a low simulation accuracy for compliance characteristic.To solve the above problems, this paper introduces the hard points and structure parameters of suspension, and establishes a suspension dynamic model based on the component characteristics; by building a more accurate of model for the suspension rubber parts, this paper researches the kinematic and compliance characteristics of suspension model. The main research contents of this paper are as follows:Firstly, according to the specific structure of suspension, this paper establishes a suspension dynamic model based on the components characteristics. There are kinematics model and statics model for suspension system. The kinematics model is based on system constraint equations and the static model can calculate the forces and moment of constraint as well as the rubber components.Secondly, this paper builds a dynamic model for rubber bushing, which can accurately describe the nonlinear and hysteresis friction characteristics of rubber components. In the studies, this paper employs the dynamic and static parameter identification method to separately identify the parameters. And the paper uses transfer function of the model to describe the relationship between deformation and force of rubber component. Eventually the paper has verified the model.Finally, the suspension dynamic model has been simulated and verified. First of all, the paper uses suspension model of ADAMS to verify kinematic model and static model. The test results indicate that the model established is correct. Then, the paper studies the kinematic and compliance characteristics of the model. In the studies, select the vertical travel of the Wheel and the force as well as the moment at the wheel center separately as the input of the kinematic and static model, the position and attitude of the spindle calculated by kinematic model are very close to the test data, and results calculated by static model prove that the characteristics of rubber components has an important effect on the compliance characteristics of suspension. The calculated results all indicate that the feasibility of the study method, which lay a certain foundation for the further research.