The Multi-domain Modeling And Simulation Of Hydraulic Brake System Based On Modelica

The vehicle brake system is the most important part for the vehicle active safety. Recently, the hydraulic brake system is widely used in passenger cars, and the process of hydraulic brake system in dynamics is very complex. The previous researches always considered the hydraulic brake system as a static model in the vehicle dynamics field, which is not effective enough to analyze the performance of the vehicle dynamics. So it is necessary to build a detailed hydraulic brake dynamic model and evaluate the dynamic response of the system.The hydraulic brake system is related to different domains, such as mechanics, hydraulics, pneumatics and so on. Recently, a multi-domain modeling and simulation language Modelica, which supports declarative and non-causal modeling and combined continuous and discrete system modeling, is widely used in engineering.The modeling and simulation platform MWorks which based on Modelica language is used to build the brake pedal, booster, master cylinder, wheel cylinder and other component models, and then hydraulic brake system is built based on those parametric component models. The dynamic response of the vehicle brake system is evaluated, and the influence of the parameters variation on the hydraulic brake system performance is studied.To study the vehicle braking performance which influenced by the dynamic characteristics of the hydraulic brake system, a passenger car multi-body model which contains the tire model, front suspension model, rear suspension model and steering system model is built, and then the vehicle multi-body model is combined with the hydraulic brake system model. The straight brake and cornering brake simulation are performed. The results show that the braking performance of this car is reasonable, and also demonstrate that the software MWorks can effectively solve the multi-domain physical problems.