The Design And Analysis Method Of Variable Ratio Curve For Variable Ratio Steering Gear

As one of the important parts of automobile steering system, steering geardetermines the overall vehicle handling performance. The variable ratio steeringsystem can meet the requirements of both steering portability and sensitiveness.Therefore, the study of the design for variable ratio curve of steering system hasimportant practical significances.This paper takes the new product development project as a support. Based on thevehicle dynamics theory, combining with the vehicle parameters, a digital designmethod for the variable ratio curve of steering system is put forward by adopting thecombination of theoretical research and experimental methods. And the variable ratiocurve model is verified in the software CarSim. The paper’s main researches includethe following:Through the research of test and objective and subjective evaluation methods ofvehicle handling stability, the evaluation contents for steering performance are created,then a quantitative evaluation system is established.According to the study of active steering system and wire control steering system,the vehicle steering dynamics model and vehicle steering system model are developedthrough steering system model and the tire model.On the basis of the study of the vehicle steady-state response characteristic, theinfluence of yaw angular velocity and lateral acceleration to the on ideal transmissionratio is analyzed. Combining with steering system model, the formulation of the curvemodel is calculated and simulated in Simulink.Finally, the calculated model is verified in the software CarSim with theenvironment of testing. And the result is satisfied.This research shows the general process of design for variable ratio curve ofsteering system. Methods of the paper have theoretical significance and engineeringvalue for the other similar product.