Modeling, Simulation And Optimization Oriented To Handling And Stability Of Sport Utility Vehicle

SUV is the sport utility vehicle. Because it not only has some functions of off-road vehicle but also partly satisfies the home recreation requirement, the SUV type is favourablely received in the market. The handling and stability is one of the critical factors affecting the driving safety of vehicles. In the manufacture of high-speed vehicles, the vehicle handling and stability is more important and is becoming the main criterion in vehicle performance evaluation. With the rapid development of the computer technique, the virtual prototype technique based on the multi-body dynamics is widely applied in the vehicle handling and stability research and in the vehicle design region.Taking into the theory and method of multi-body system dynamics, the multi-body system models of a SUV type front suspension and full vehicle are established with ADAMS software in this dissertation. And the main alignment parameters and dynamic simulations are performed separately. The sensitivity analysis, the optimization design of front suspension performance as well as the full vehicle dynamic performance are finished. This study gives an efficient method which has the theortical guidance value for the SUV type research and development.It is analyzed about the market situation and the performance nature of SUV type, the R&D technique presentation of the automobile as well as the relevance advanced technology. A comparatively whole set of modeling and simulation method for SUV type is suggested. It is a substantial foundation of SUV modeling and simulation.The multi-body system models of a SUV type front suspension are set up. It is analyzed for the model relevance parameters to be selected and to be defined. The main front-wheel alignment parameters of front suspension are determined and the simulation is finished. The simulation results show that the main front-wheel alignment parameters of this SUV type are basically reasonable and satisfy the design requirement. Using the optimization design method based on the sensitivity analysis, the optimization design for the main performance of the front suspension is completed. Some optimal results having higher guiding and practical value are obtained.The multi-body system dynamic model of a SUV full vehicle is founded. The relevance sub-system models of full vehicle are analyzed and are set up. The proper model parameters and modeling methods are chosen. The main handling and stability parameters of the full vehicle are determined and the handling stability simulation of the full vehicle is accomplished. The key theory and technique of the back suspension model are studied. A simple, rapid and accurate kind of medium-plane modeling method is submitted. It is shown by the simulation results that the handling and stability of the full vehicle is fair and is able to satisfy the design requirement.By the multi-body system models of SUV type front suspension and full vehicle, the sensitivity analysis for the main performance parameters of the front suspension and the full vehicle handling and stability is conducted. It is discussed for the design variables to affect the front suspension performance parameters and the full vehicle handling and stability. The important factors are discovered. At last, the dynamic optimization design of the full vehicle handling and stability is fulfuled. The valuable guidance is supplied for the design and R&D of the SUV type.Through the simulating calculation and the analysis, the built multi-body models of the SUV front suspension and the full vehicle are accorded with the real vehicle type on the main performance and on the variation trend. The models and the results are confirmed by the manufacturing corporation of the SUV type.