The Dynamic Simulation And Optimization Study For Vehicle Suspension Based On Genetic Algorithm

The car is a complex multibody systems and the stability of the vehicle is influenced by the tyres, suspension, steering system, engine and driveline system.The function of suspension system is transferring vertical,longitudinal and lateral reaction force and torque which road act on wheels to the frames to ensure the normal running.So the design quality of the suspension system have a direct impact on the vehicle dynamic performance,such as handling stability,ride comfort, safety and tire life etc.Therefore,studying the dynamic performance of suspension system through the simulation analysis method and optimizing suspension system with genetic algorithm have a important significance on improving the handling stability and safety of cars.This paper firstly introduced the background of the subject research,virtual prototype technology and basic theory of multi-body dynamics software ADAMS,putted forward the macpherson suspension virtual design and test platform and summarized the research content and method of this paper.Based on multi-body system dynamics theory and ADAMS/Car,simulation model of the vehicle suspension systems and whole vehicle dynamics model have been established including macpherson suspension model,double wishbone suspension model,steering system model,tire model,body model and road model.And then based on simulation model of the vehicle suspension systems,simulation analysis of wheel travel test on the system was also made on macpherson suspension model,double wishbone suspension model.The curve diagrams which included front wheel alignment parameter and suspension characteristic along with the wheel center changed played the role of preliminary evaluation of suspension system.Full-Vehicle simulation analyses of step steer,impulse steer,cornering with steer release,constant-radius cornering were tested on the whole vehicle dynamics model.It made a further evaluation to suspension system.At last making the suspension component hard point as design variables and absolute value weighted sum of wheel position parameters relative to the variation of balance position as optimization objectives.Suspension system had been optimized with genetic algorithm.The contrast of simulation results showed that suspension performance was improved by the optimization and achieved the optimization purpose.Thus it proved the feasibility of the optimization scheme, and completed the simulation study and optimization design for vehicle suspension.