Modeling and simulation of hydraulic components for passenger cars

Abstract

Passenger car suspensions contain a number of hydraulic components, such as dampers, hydraulic rubber mounts, power steering and active suspension units. Modeling and simulation of these hydraulic components is reviewed and further developed on the basis of one-dimensional flows represented in the time domain, which is an effective and reliable approach for the design and analysis of automotive fluid power systems. The components of suspension systems are assembled by multi-port connectors for numerical analysis. Then, the solution by standard integration codes may result in fluid mass losses, which do not exist in reality. Therefore, an implicit integration code conserving the fluid mass is presented. The validated hydraulic component model blocks can be exported to a wide range of simulation programs without encountering problems. An active tire tilt control (ATTC) system is presented in detail. The deployment of automotive fluid power simulation allows for suspension system and vehicle dynamics design in virtual reality before a prototype vehicle is built. It is shown that accurate component models are required as a sound basis for the process chain of modeling, validation, and parameter identification, which results in full vehicle simulation. The excellent performance of ATTC vehicles has proven the quality of the predictive simulation results used for the performance optimization of this chassis system.